As filed with the Securities and Exchange Commission on August 13, 2021

Registration No. 333-                

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM S-4

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

ZOOM VIDEO COMMUNICATIONS, INC.

(Exact Name of Registrant as Specified in Its Charter)

55 Almaden Boulevard, 6th Floor

San Jose, California 95113

Telephone: (888) 799-9666

(Address, including Zip Code, and Phone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Eric S. Yuan

President and Chief Executive Officer

55 Almaden Boulevard, 6th Floor

San Jose, California 95113

Telephone: (888) 799-9666

(Name, Address, including Zip Code, and Telephone Number, including Area Code, of Agent for Service)

With a copy to:

Approximate date of commencement of proposed sale of the securities to the public: As soon as practicable after this registration statement is declared effective.

If the securities being registered on this form are being offered in connection with the formation of a holding company and there is compliance with General Instruction G, please check the following box.  ☐

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

If this form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.  ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

If applicable, place an X in the box to designate the appropriate rule provision relied upon in conducting this transaction:

Exchange Act Rule 13e-4(i) (Cross-Border Issuer Tender Offer)  ☐

Exchange Act Rule 14d-1(d) (Cross-Border Third-Party Tender Offer)  ☐

CALCULATION OF REGISTRATION FEE

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with section 8(a) of the Securities Act of 1933, as amended, or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

The information in the accompanying proxy statement/prospectus is not complete and may be changed. These securities may not be issued until the registration statement filed with the U.S. Securities and Exchange Commission is effective. The accompanying proxy statement/prospectus is not an offer to sell these securities and does not constitute the solicitation of offers to buy these securities in any jurisdiction where the offer or sale is not permitted.

PRELIMINARY—SUBJECT TO COMPLETION, DATED AUGUST 13, 2021

LETTER TO STOCKHOLDERS OF FIVE9, INC.

Dear Five9 Stockholders:

On July 16, 2021, Zoom Video Communications, Inc. (which we refer to as “Zoom”), Summer Merger Sub, Inc. (which we refer to as “Merger Sub”) and Five9, Inc. (which we refer to as “Five9”) entered into an Agreement and Plan of Merger (which, as it may be amended from time to time, we refer to as the “merger agreement”). The merger agreement provides for the merger of Merger Sub with and into Five9, with Five9 continuing as the surviving company and a wholly owned subsidiary of Zoom (which we refer to as the “merger”).

Five9 stockholders as of the close of business on                 , 2021 (which we refer to as the “record date”) are invited to virtually attend a special meeting of Five9 stockholders on                , 2021, at                , Pacific Time, to consider and vote upon a proposal to adopt the merger agreement and approve the transactions contemplated thereby, a non-binding advisory proposal to approve certain compensation that may be paid or become payable to Five9’s named executive officers that is based on or otherwise relates to the merger and a proposal to approve the adjournment of the special meeting, if necessary or appropriate, to solicit additional proxies if there are not sufficient votes at the time of the special meeting to adopt the merger agreement and approve the transactions contemplated thereby.

Subject to the terms and conditions of the merger agreement, at the effective time of the merger (which we refer to as “effective time”), each outstanding share of Five9 common stock (other than shares of Five9 common stock owned directly or indirectly by Zoom, Five9 or Merger Sub immediately prior to the effective time or shares of Five9 common stock owned by any direct or indirect wholly owned subsidiary of Zoom (other than Merger Sub) or of Five9) will be converted in the merger into the right to receive 0.5533 shares of Zoom Class A common stock, without interest, and, if applicable, an amount in cash, rounded down to the nearest cent, in lieu of any fractional share interest in Zoom Class A common stock to which such holder otherwise would have been entitled (which we refer to as “merger consideration”).

Based on the closing price of Zoom Class A common stock on July 16, 2021, the last full unaffected trading day prior to announcing the transaction, the value of the per share merger consideration payable to holders of Five9 common stock upon completion of the merger was approximately $200.28. Based on the closing price of Zoom Class A common stock on                 , the last practicable date before the date of the proxy statement/prospectus accompanying this notice, the value of the merger consideration payable to holders of Five9 common stock upon completion of the merger was approximately $                . Five9 stockholders should obtain current stock price quotations for Zoom Class A common stock and Five9 common stock. Zoom’s common stock is traded on The Nasdaq Global Select Market (which we refer to as “Nasdaq”) under the symbol “ZM,” and Five9 common stock is traded on The Nasdaq Global Market under the symbol “FIVN.”

The Five9 board of directors has unanimously determined that the merger agreement and the transactions contemplated by the merger agreement, including the merger, are fair to, and in the best interests of, Five9 and its stockholders and unanimously recommends that Five9 stockholders vote “FOR” each of the proposals described in the accompanying proxy statement/prospectus.

Five9 will hold a virtual special meeting of its stockholders to consider certain matters relating to the merger. Zoom and Five9 cannot complete the merger unless, among other things, Five9 stockholders adopt the merger agreement and approve the transactions contemplated thereby.

Your vote is very important. To ensure your representation at the special meeting, complete and return the enclosed proxy card or submit your proxy by phone or the Internet. Please vote promptly whether or not you expect to virtually attend the special meeting. Submitting a proxy now will not prevent you from being able to vote at the special meeting.

The proxy statement/prospectus accompanying this notice is also being delivered to Five9’s stockholders as Zoom’s prospectus for its offering of shares of Zoom Class A common stock in connection with the merger.

The obligations of Zoom and Five9 to complete the merger are subject to the satisfaction or waiver of the conditions set forth in the merger agreement, a copy of which is included as part of the accompanying proxy statement/prospectus. The proxy statement/prospectus provides you with detailed information about the merger. It also contains or references information about Zoom and Five9 and certain related matters. You are encouraged to read the proxy statement/prospectus, including the information incorporated by reference therein, carefully and in its entirety. In particular, you should carefully read the section entitled “Risk Factors” for a discussion of risks you should consider in evaluating the merger and the issuance of shares of Zoom Class A common stock in connection with the merger and how they will affect you.

Sincerely,

/s/ Rowan Trollope

Rowan Trollope

Chief Executive Officer

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the securities to be issued under the accompanying proxy statement/prospectus or passed upon the adequacy or accuracy of the disclosure in this document. Any representation to the contrary is a criminal offense.

The proxy statement/prospectus is dated                 , 2021 and is first being mailed to stockholders of Five9 on or about                 , 2021.

Five9, Inc.

NOTICE OF THE SPECIAL MEETING OF STOCKHOLDERS

TO BE HELD VIRTUALLY VIA THE INTERNET ON

Notice is hereby given that a special meeting of stockholders of Five9, Inc. (which we refer to as “Five9”) will be held on                 , 2021 at                 , Pacific Time via a live interactive audio webcast on the Internet (which we refer to as the “Five9 special meeting”). You will be able to vote and submit your questions at                  during the meeting. We are holding the special meeting for the following purposes, which are more fully described in the accompanying proxy statement/prospectus:

Five9 stockholder approval of the merger proposal is required to complete the merger as contemplated by the merger agreement. Five9 stockholders will also be asked to approve the non-binding compensation advisory proposal and, if necessary or appropriate, the adjournment proposal. Five9 will transact no other business at the Five9 special meeting. The record date for the Five9 special meeting has been set as                 , 2021 (which we refer to as the “record date”). Only Five9 stockholders of record as of the close of business on the record date are entitled to notice of, and to vote at, the Five9 special meeting via the Five9 special meeting website or any adjournments and postponements of the Five9 special meeting. For additional information regarding the Five9 special meeting, see the section entitled “Special Meeting of Five9 Stockholders.”

The Five9 board of directors unanimously recommends that you vote “FOR” the merger proposal, “FOR” the non-binding compensation advisory proposal and “FOR” the adjournment proposal.

The Five9 proposals are described in more detail in the accompanying proxy statement/prospectus, which you should read carefully and in its entirety before you vote. A copy of the merger agreement is attached as Annex A to the accompanying proxy statement/prospectus.

PLEASE VOTE AS PROMPTLY AS POSSIBLE, WHETHER OR NOT YOU PLAN TO ATTEND THE FIVE9 SPECIAL MEETING. IF YOU LATER DESIRE TO REVOKE OR CHANGE YOUR PROXY FOR ANY REASON, YOU MAY DO SO IN THE MANNER DESCRIBED IN THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS. FOR FURTHER INFORMATION CONCERNING THE PROPOSALS BEING VOTED UPON, USE OF THE PROXY AND OTHER RELATED MATTERS, YOU ARE URGED TO READ THE ACCOMPANYING PROXY STATEMENT/PROSPECTUS.

REFERENCES TO ADDITIONAL INFORMATION

This proxy statement/prospectus incorporates by reference important business and financial information about Zoom Video Communications, Inc. (which we refer to as “Zoom”) and Five9, Inc. (which we refer to as “Five9”) from other documents that are not included in or delivered with this proxy statement/prospectus, including documents that Zoom and Five9 have filed with the U.S. Securities and Exchange Commission (which we refer to as the “SEC”). For a listing of documents incorporated by reference herein, see the section entitled “Where You Can Find More Information.” This information is available for you to review free of charge through the SEC’s website at www.sec.gov.

You may request copies of this proxy statement/prospectus and any of the documents incorporated by reference herein or other information concerning Zoom or Five9, without charge, upon written or oral request to the applicable company’s principal executive offices. The respective addresses and phone numbers of such principal executive offices are listed below.

To obtain timely delivery of these documents before the Five9 special meeting, Five9 stockholders must request the information no later than                 , 2021 (which is five business days before the date of the Five9 special meeting).

In addition, if you have questions about the merger or this proxy statement/prospectus, would like additional copies of this proxy statement/prospectus or need to obtain proxy cards or other information related to the proxy solicitation, contact Innisfree M&A Incorporated, the proxy solicitor for Five9, toll-free at (877) 750-8197, or for brokers and banks, collect at (212) 750-5833. You will not be charged for any of these documents that you request.

ABOUT THIS PROXY STATEMENT/PROSPECTUS

This document, which forms part of a registration statement on Form S-4 filed with the SEC by Zoom (File No. 333-                ) (which we refer to as the “registration statement”), constitutes a prospectus of Zoom under Section 5 of the Securities Act of 1933, as amended (which we refer to as the “Securities Act”) with respect to the shares of Class A common stock of Zoom, par value $0.001 per share (which we refer to as “Zoom Class A common stock”) to be issued to Five9 stockholders pursuant to the Agreement and Plan of Merger, dated as of July 16, 2021 (which, as it may be amended from time to time, we refer to as the “merger agreement”), among Zoom, Summer Merger Sub, Inc. (which we refer to as “Merger Sub”) and Five9.

This document also constitutes a notice of meeting and proxy statement of Five9 under Section 14(a) of the Securities Exchange Act of 1934, as amended (which we refer to as the “Exchange Act”).

Zoom has supplied all information contained or incorporated by reference herein relating to Zoom, and Five9 has supplied all information contained or incorporated by reference herein relating to Five9.

You should rely only on the information contained in or incorporated by reference herein in connection with any vote, the giving or withholding of any proxy or any investment decision in connection with the merger agreement. Zoom and Five9 have not authorized anyone to provide you with information that is different from that contained in or incorporated by reference herein. This proxy statement/prospectus is dated as of                 , 2021, and you should not assume that the information contained in this proxy statement/prospectus is accurate as of any date other than such date unless otherwise specifically provided herein. Further, you should not assume that the information incorporated by reference herein is accurate as of any date other than the date of the incorporated document. Neither the mailing of this proxy statement/prospectus to Five9 stockholders nor the issuance by Zoom of shares of Zoom Class A common stock pursuant to the merger agreement will create any implication to the contrary.

All currency amounts referenced in this proxy statement/prospectus are in U.S. dollars.

TABLE OF CONTENTS

-i-

-ii-

-iii-

-iv-

QUESTIONS AND ANSWERS ABOUT THE MERGER AND THE FIVE9 SPECIAL MEETING

The following are answers to certain questions that you may have regarding the merger, the merger agreement, the transactions contemplated by the merger agreement and the Five9 special meeting. You are urged to read carefully the remainder of this document because the information in this section may not provide all the information that might be important to you in determining how to vote. Additional important information is also contained in the annexes to, and the documents incorporated by reference in, this document.

The merger agreement must be adopted by the Five9 stockholders in accordance with the General Corporation Law of the State of Delaware (which we refer to as the “DGCL”) in order for the merger to be consummated. Five9 is holding a virtual special meeting of its stockholders (which we refer to as the “Five9 special meeting”) to obtain that approval. Five9 stockholders will also be asked to vote on a non-binding advisory proposal to approve certain compensation that may be paid or become payable to Five9’s named executive officers that is based on or otherwise relates to the merger and to approve the adjournment of the special meeting, from time to time, if necessary or appropriate, to solicit additional proxies if there are not sufficient votes at the time of the special meeting to approve the merger proposal. Your vote is very important. We encourage you to submit a proxy to have your shares of common stock, par value $0.001 per share, of Five9 (which we refer to as “Five9 common stock”) voted as soon as possible.

A:    The Five9 special meeting will be held virtually via the Internet at                 Pacific Time, on                 , 2021. The Five9 special meeting will be held solely via live webcast and there will not be a physical meeting location. Five9 stockholders will be able to attend the Five9 special meeting online and vote their shares electronically during the meeting by visiting                 , which we refer to as the “Five9 special meeting website.”

A:    The Five9 stockholders are being asked to consider and vote on:

-1-

Under the current rules of applicable stock market exchanges, brokers, banks or other nominees may use their discretion to vote “uninstructed” shares (i.e., shares of record held by banks, brokers or other nominees, but with respect to which the beneficial owner of such shares has not provided instructions on how to vote on a particular proposal) with respect to matters that are considered to be “routine,” but not with respect to “non-routine” matters. All of the proposals currently expected to be voted on at the Five9 special meeting are non-routine matters under applicable stock market exchange rules for which brokers do not have discretionary authority to vote, and therefore it is not expected that there will be any broker non-votes at the Five9 special meeting. However, if there are any broker non-votes, they will have (i) the same effect as a vote “AGAINST” the merger proposal, (ii) no effect on the non-binding compensation advisory proposal, and (iii) no effect on the Five9 adjournment proposal.

The non-binding compensation advisory proposal. Approval of the non-binding compensation advisory proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote. As an advisory vote, this proposal is not binding upon Five9 or the Five9 board or Zoom or the board of directors of Zoom (which we refer to as the “Zoom board”), and approval of this proposal is not a condition to completion of the merger.

The adjournment proposal. Approval of the adjournment proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote.

-2-

If you receive the merger consideration and would otherwise be entitled to receive a fractional share of Zoom Class A common stock, you will receive cash in lieu of such fractional share, and you will not be entitled to dividends, voting rights or any other rights in respect of such fractional share. For additional information regarding the merger consideration, see the sections entitled “The Merger—Consideration to Five9 Stockholders” and “The Merger Agreement—Merger Consideration.”

At the effective time, all other Five9 options that are outstanding and unexercised immediately prior to the effective time will be assumed and automatically converted into an option (which we refer to as an “adjusted option”) to purchase a number of shares of Zoom Class A common stock determined by multiplying the number of shares covered by the Five9 option by the exchange ratio, rounded down to the nearest whole share, at a per share exercise price equal to the per share exercise price of the Five9 option divided by the exchange ratio, rounded up to the nearest whole cent. The adjusted options will otherwise be subject to the same terms and conditions as were applicable to the corresponding Five9 option prior to the effective time, including vesting terms.

As used in this proxy statement/prospectus, (1) the “Zoom trading price” means the volume weighted average closing price of Zoom Class A common stock as reported on the Nasdaq Global Select Market (which we refer to as “Nasdaq”) for the 10 consecutive trading day period ending on the trading day immediately preceding the effective time, (2) the “exchange ratio” means 0.5533 and (3) the “per share cash equivalent consideration” means the product of (a) the exchange ratio and (b) the Zoom trading price. See the section entitled “The Merger Agreement—Treatment of Five9 Equity Awards” for more information.

-3-

At the effective time, each Five9 RSU award (other than any such award held by any non-employee director) will be assumed and converted into an award of restricted stock units (each of which we refer to as an “adjusted RSU award”) with respect to a number of shares of Zoom Class A common stock (rounded to the nearest whole share) determined by multiplying the number of shares of Five9 common stock subject to the Five9 RSU award by the exchange ratio. Each adjusted RSU award will be subject to the same terms and conditions as were applicable to the corresponding Five9 RSU award prior to the effective time, including vesting terms.

See the section entitled “The Merger Agreement—Treatment of Five9 Equity Awards” for more information.

See the section entitled “The Merger Agreement—Treatment of Five9 Equity Awards” for more information.

-4-

-5-

Shares of Five9 common stock held directly in your name as the stockholder of record as of the close of business on                , 2021, the Five9 record date, may be voted at the Five9 special meeting via the Five9 special meeting website. If you choose to attend the Five9 special meeting and vote your shares via the Five9 special meeting website, you will need the 16-digit control number included on your proxy card. If you are a beneficial owner of Five9 common stock but not the stockholder of record of such shares of Five9

-6-

common stock, you have the right to direct your broker, bank, or other nominee as to how to vote your shares if you follow the instructions you receive from your broker, bank, or nominee. Follow the instructions set forth by your broker, bank or nominee on your enclosed voting instruction form for the methods by which you can vote.

In order to be counted, proxies submitted by telephone or Internet must be received by 11:59 p.m. Eastern Time on                , 2021. Proxies submitted by U.S. mail must be received before the start of the Five9 special meeting.

If you are a street name stockholder, please follow the instructions from your broker, bank, or other nominee set forth on your enclosed voting instruction form for the methods by which you can vote.

Street Name Stockholders. If shares of Five9 common stock are held on your behalf in a brokerage account or by a bank or other nominee, you are considered to be the beneficial owner of shares that are held in “street name,” and the notice was forwarded to you by your broker or nominee, who is considered the stockholder of record with respect to those shares. As the beneficial owner, you have the right to direct your broker, bank, or other nominee as to how to vote your shares if you follow the instructions you receive from your broker, bank, or nominee set forth on your enclosed voting instruction form.

Stockholders of record. For shares of Five9 common stock held directly, complete, sign, date and return each proxy card (or cast your vote by phone or the Internet as provided on each proxy card) or otherwise follow the voting instructions provided in this proxy statement/prospectus in order to ensure that all of your shares of Five9 common stock are voted.

Shares in “street name.” For shares of Five9 common stock held in “street name” through a broker, bank or other nominee, follow the instructions provided by your broker, bank or other nominee to vote your shares.

-7-

Your shares of Five9 common stock will be voted “FOR” the approval of the merger proposal, “FOR” the approval of the non-binding compensation advisory proposal and “FOR” the adjournment proposal.

If your shares are held in an account at a bank, broker or other nominee and you have delivered your voting instruction form or otherwise given instruction on how to vote your shares to your bank, broker or other nominee or your applicable plan administrator, you should contact your bank, broker or other nominee or your applicable plan administrator to change your vote.

-8-

No ruling has been, or will be, sought by Five9 or Zoom from the IRS with respect to the merger and there can be no assurance that the IRS will not challenge the qualification of the merger as a “reorganization” under Section 368(a) of the Code or that a court would not sustain such a challenge. If the IRS successfully challenges the reorganization status of the merger, U.S. holders (as defined under the section entitled “Material U.S. Federal Income Tax Consequences of the Merger”) will be treated as if they sold their Five9 common stock in a fully taxable transaction.

Assuming that the merger qualifies as a “reorganization” within the meaning of Section 368(a) of the Code, a U.S. holder will generally not recognize any gain or loss for U.S. federal income tax purposes on the receipt of Zoom Class A common stock in exchange for Five9 common stock in the merger, except that such holder of Five9 common stock will generally recognize gain or loss with respect to cash received in lieu of fractional shares of Zoom Class A common stock.

For additional information, see the section entitled “Material U.S. Federal Income Tax Consequences of the Merger” for a more complete discussion of the material U.S. federal income tax consequences of the merger. The tax consequences to you of the merger will depend on your particular facts and circumstances. Please consult your own tax advisor as to the tax consequences of the merger in your particular circumstances, including the applicability and effect of U.S. federal, state, local and non-U.S. income and other tax laws.

-9-

If you are a holder of record of Five9 book-entry shares which are not held through DTC, the exchange agent will deliver to you, as soon as practicable after the effective time, (i) a notice advising you of the effectiveness of the merger, (ii) a statement reflecting the aggregate whole number of shares of Zoom Class A common stock (which will be in uncertificated book-entry form) that you have a right to receive pursuant to the merger agreement and (iii) a check in the amount equal to the cash payable in lieu of any fractional shares of Zoom Class A common stock and any dividends and other distributions on the shares of Zoom Class A common stock issuable to you as merger consideration.

No interest will be paid or accrued on any amount payable for shares of Five9 common stock eligible to receive the merger consideration pursuant to the merger agreement.

For additional information on the exchange of Five9 common stock for the merger consideration, see the section entitled “The Merger Agreement—Merger Consideration.”

Zoom has never paid any cash dividends on its common stock. The Zoom board currently intends to retain any future earnings to support operations and to finance the growth and development of its business and does not intend to pay cash dividends on its common stock for the foreseeable future. Any future determination related to its dividend policy will be made at the discretion of the Zoom board.

-10-

Innisfree M&A Incorporated

501 Madison Avenue, 20^th Floor

New York, New York 10022

(877) 750-8197

Banks and Brokers: (212) 750-5833

-11-

-12-

-13-

-14-

-15-

-16-

-17-

-18-

-19-

-20-

-21-

-22-

-23-

SELECTED UNAUDITED PRO FORMA CONDENSED COMBINED FINANCIAL DATA

The following selected unaudited pro forma condensed combined financial data was prepared using the acquisition method of accounting with Zoom as the accounting acquirer. The selected unaudited pro forma condensed combined balance sheet data assumes the merger of Zoom and Five9 took place on April 30, 2021. The selected unaudited pro forma condensed combined statements of operations data assumes the merger of Zoom and Five9 took place on February 1, 2020.

The following selected unaudited pro forma condensed combined financial data is for illustrative purposes only and is not necessarily indicative of the combined financial position or results of operations of future periods or the results that actually would have been realized had the entities been a single entity during these periods. Future results may vary significantly from the results reflected because of various factors, including those discussed in the section entitled “Risk Factors.” The following selected unaudited pro forma condensed combined financial data should be read in conjunction with the sections entitled “The Merger Agreement” and “Unaudited Pro Forma Condensed Combined Financial Information” and related notes included in this proxy statement/prospectus.

-24-

COMPARATIVE HISTORICAL AND UNAUDITED PRO FORMA AND PER SHARE FINANCIAL INFORMATION

The following tables summarize selected per share data for (i) Zoom for the year ended January 31, 2021 and Five9 for the year ended December 31, 2020, in each case, on an audited historical basis, and unaudited historical financial information of Zoom for the three months ended April 30, 2021 and Five9 for the three months ended March 31, 2021, (ii) Zoom for the year ended January 31, 2021 and the three months ended April 30, 2021 on an unaudited pro forma combined basis giving effect to the merger using the acquisition method of accounting and (iii) Five9 for the year ended December, 31 2020 and the three months ended March 31, 2021 on an unaudited pro forma equivalent basis based on the exchange ratio of 0.5533 of a share of Zoom Class A common stock per share for Five9 common stock.

The following table reflects historical information about basic and diluted net income per share attributable to common stockholders for the fiscal year ended January 31, 2021 and the three months ended April 30, 2021, in the case of Zoom, and for the fiscal year ended December 31, 2020 and the three months ended March 31, 2021, in the case of Five9, and the book value per common share as of April 30, 2021 in the case of Zoom and as of March 31, 2021, in the case of Five9, in each case, on a historical basis, and for the combined company on an unaudited pro forma condensed combined basis after giving effect to the merger. The pro forma data of the combined company assumes the merger was completed on February 1, 2020 and was derived by combining the historical consolidated financial information of Zoom and Five9. For a discussion of the assumptions and adjustments made in preparing the unaudited pro forma combined financial information presented in this document, see the section entitled “Unaudited Pro Forma Condensed Combined Financial Information.”

The unaudited pro forma per share data below is presented for illustrative purposes only. The pro forma adjustments to the statement of operations data are based on the assumption that the merger was completed on February 1, 2020, and the pro forma adjustments to the balance sheet data are based on the assumption that the merger was completed on April 30, 2021.

Either company’s actual historical financial condition and results of operations may have been different had the companies always been combined. You should not rely on this information as being indicative of the historical financial condition and results of operations that would have actually been achieved or of the future results of Zoom after the completion of the merger.

You should read the information below together with the historical consolidated financial statements and related notes of Zoom and Five9 as of and for the applicable periods, which have been incorporated by reference into this proxy statement/prospectus, along with the information in the section entitled “Unaudited Pro Forma Condensed Combined Financial Information” and related notes included in this proxy statement/prospectus.

-25-

COMPARATIVE PER SHARE MARKET PRICE AND DIVIDEND INFORMATION

Market Prices

Zoom Class A common stock is listed on Nasdaq under the symbol “ZM,” and Five9 common stock is listed on Nasdaq under the symbol “FIVN.” The Zoom Class B common stock (which, together with the Zoom Class A common stock, we refer to as the “Zoom common stock”) is not publicly traded but converts, on a one-for-one basis, into Zoom Class A common stock at the election of the holder or upon the sale or other transfer (subject to certain exceptions) of such shares.

The following table sets forth the closing sale price per share of Zoom Class A common stock and Five9 common stock reported on Nasdaq as of (1) July 16, 2021, the trading day before the public announcement of the execution of the merger agreement and (2) August 12, 2021, the latest practicable trading date before the date of this proxy statement/prospectus. The table also shows the estimated implied value of the per share merger consideration for each share of Five9 common stock as of the same two days. This implied value was calculated by multiplying the closing prices per share of Zoom Class A common stock on those dates by an exchange ratio of 0.5533, without interest.

The market prices of Zoom Class A common stock and Five9 common stock have fluctuated since the date of the announcement of the merger agreement and will continue to fluctuate from the date of this proxy statement/prospectus to the date of the Five9 special meeting and the date the merger is completed and thereafter (in the case of Zoom Class A common stock). The value of the merger consideration to be received in exchange for each share of Five9 common stock will fluctuate with changes in the market value of Zoom Class A common stock until the last trading day before the merger is complete.

The value of the merger consideration to be received in exchange for each share of Five9 common stock when received by Five9 stockholders after the merger is completed could be greater than, less than or the same as shown in the table above. Accordingly, Five9 stockholders are advised to obtain current market quotations for Zoom Class A common stock and Five9 common stock in deciding whether to vote in favor of the merger proposal.

Dividends

Zoom has never paid any cash dividends on its common stock. The Zoom board currently intends to retain any future earnings to finance the operation and expansion of Zoom’s business, and Zoom does not expect to declare or pay any dividends in the foreseeable future. Any future determination related to Zoom’s dividend policy will be made at the discretion of the Zoom board.

Five9 has never paid any cash dividends on its common stock. Under the terms of the merger agreement, prior to the completion of the merger, Five9 is not permitted to declare, set aside, authorize, make or pay any dividend or other distribution without the consent in writing of Zoom.

-26-

RISK FACTORS

In addition to the other information contained in or incorporated by reference herein, including the matters addressed in the section entitled “Cautionary Statement Regarding Forward-Looking Statements,” Five9 stockholders should carefully consider the following risks before deciding how to vote with respect to the merger proposal and non-binding compensation advisory proposal to be considered and voted on at the Five9 special meeting, together with general investment risks and all of the other information included in, or incorporated by reference into this proxy statement/prospectus. This proxy statement/prospectus also contains forward-looking statements that involve risks and uncertainties. Please read the section entitled “Cautionary Statement Regarding Forward-Looking Statements.”

The risks described below are certain material risks, although not the only risks, relating to the transactions contemplated by the merger agreement and each of Zoom, Five9 and the surviving company in relation to the merger. The risks described below are not the only risks that Zoom or Five9 currently face or that Zoom or the surviving company will face after the completion of the merger. Additional risks and uncertainties not currently known or that are currently expected to be immaterial may also materially and adversely affect the business, financial condition and results of operations of Zoom or the surviving company, or the market price of Zoom Class A common stock following the completion of the merger.

If any of the following risks and uncertainties develop into actual events, these events could have a material adverse effect on the business, financial condition and results of operations of Zoom, Five9 and/or the surviving company. In addition, past financial performance may not be a reliable indicator of future performance, and historical trends should not be used to anticipate results or trends in future periods.

Risk Factors Relating to the Merger

The merger consideration is fixed and will not be adjusted. Because the market price of Zoom Class A common stock may fluctuate, Five9 stockholders cannot be sure of the market value of the stock consideration they will receive in exchange for their shares of Five9 common stock in connection with the transactions.

In connection with the merger, each share of Five9 common stock issued and outstanding immediately prior to the effective time (other than cancelled shares or converted shares) will be converted into the right to receive 0.5533 shares of Zoom Class A common stock, without interest. Accordingly, the market value of the merger consideration that you will receive will vary based on the price of Zoom Class A common stock at the time you receive the merger consideration. The market price of Zoom Class A common stock may decline after the date of this document, after you exchange your shares and/or after the closing.

A decline in the market price of Zoom Class A common stock could result from a variety of factors beyond Zoom’s control, including, among other things, the possibility that Zoom may not achieve the expected benefits of the acquisition of Five9 as rapidly or to the extent anticipated, Five9’s business may not perform as anticipated following the closing, the effect of Zoom’s acquisition of Five9 on Zoom’s financial results may not meet the expectations of Zoom, financial analysts or investors, or the addition and integration of Five9’s business may be unsuccessful, may take longer or be more disruptive than anticipated, as well as numerous factors affecting Zoom and its businesses that are unrelated to Five9.

If the merger is completed, there will be a lapse of time between each of the date of this proxy statement/prospectus, the date on which Five9 stockholders vote to approve the merger proposal at the Five9 special meeting, and the date on which Five9 stockholders entitled to receive the merger consideration actually receive the merger consideration. The market value of shares of Zoom Class A common stock may decline during and after these periods as a result of a variety of factors, and consequently, at the time Five9 stockholders must decide whether to approve the merger proposal, they will not know the actual market value of any merger consideration they will receive when the merger is completed. The actual value of any merger consideration received by Five9 stockholders at the completion of the merger will depend on the market value of the shares of Zoom Class A common stock at that time.

-27-

You are urged to obtain current market quotations for shares of Five9 common stock and for shares of Zoom Class A common stock.

If the merger is completed, Five9 stockholders will receive Zoom shares as the merger consideration and will accordingly become Zoom stockholders. Zoom Class A common stock may be affected by different factors than those that affect Five9 common stock, and Zoom stockholders will have different rights than Five9 stockholders.

Upon consummation of the transactions, Five9 stockholders will receive Zoom shares as the merger consideration and will accordingly become Zoom stockholders. Zoom’s business differs from that of Five9, and Zoom’s results of operations and stock price may be adversely affected by factors different from those that would affect Five9’s results of operations and stock price. Following the completion of the merger, Five9 will be part of a larger company, so decisions affecting Five9 may be made in respect of the larger combined business as a whole rather than the Five9 business individually. For a discussion of the businesses of Zoom and Five9 and of some important factors to consider in connection with those businesses, see the section entitled “Information About the Companies” and the documents incorporated by reference in the section entitled “Where You Can Find More Information,” including, in particular, in the sections entitled “Risk Factors” in (i) Zoom’s Annual Report on Form 10-K for the year ended January 31, 2021 and Quarterly Reports on Form 10-Q for the quarter ended April 30, 2021 and (ii) Five9’s Annual Report on Form 10-K for the year ended December 31, 2020 and Quarterly Reports on Form 10-Q for the quarters ended March 31, 2021 and June 30, 2021.

In addition, Five9 stockholders receiving shares of Zoom Class A common stock will have rights as Zoom stockholders that differ from the rights they had as Five9 stockholders before the transactions. For a comparison of the rights of Zoom stockholders to the rights of Five9 stockholders, see the section entitled “Comparison of Stockholders’ Rights.”

Five9 stockholders will be forfeiting all rights with respect to their shares of Five9 common stock other than the right to receive the merger consideration, including the right to participate directly in any earnings or future growth of Five9.

If the merger is completed, Five9 stockholders will cease to have any equity interest in Five9 and will not participate in its earnings or any future growth, except indirectly through ownership of Zoom shares received as part of the merger consideration.

Five9 directors and officers potentially have interests in the transaction that differ from, or are in addition to, the interests of Five9 stockholders generally.

You should be aware that some of the officers and directors of Five9 may be deemed to have interests in the merger that are different from, or in addition to, your interests as a Five9 stockholder. These interests may include, among others, agreements that certain officers have entered into with Five9 that provide for the acceleration of Five9 options and Five9 RSU awards in the event the officer experiences a qualifying termination of employment within a specified period following a change of control of Five9, payments of severance benefits under Five9’s change-in-control severance agreements with executive officers, agreements that certain executive officers have entered into with Zoom that provide for grants of Zoom equity awards following the effective time and certain indemnification obligations. For additional information, see the sections entitled “The Merger—Interests of Five9 Directors and Executive Officers in the Merger” and “The Merger Agreement—Employee Matters.”

As of August 6, 2021, Five9 directors, executive officers, and their respective affiliates, as a group, beneficially held and were entitled to vote 428,064 shares of Five9 common stock, representing 0.63% of the voting power of Five9 common stock.

-28-

Five9 stockholders will have a reduced ownership and voting interest in Zoom as compared to their ownership and voting interest in Five9 and will exercise less influence over management.

Currently, Five9 stockholders have the right to vote in the election of the Five9 board and the power to approve or reject any matters requiring stockholder approval under Delaware law and the Five9 certificate of incorporation and bylaws. Upon completion of the merger, each Five9 stockholder who receives shares of Zoom Class A common stock in the merger will become a stockholder of Zoom with a percentage ownership of Zoom that is smaller than the Five9 stockholder’s current percentage ownership of Five9. Based on the number of issued and outstanding shares of Zoom and Five9 common stock as of August 10, 2021, the last practicable date before the date of the proxy statement/prospectus, and the exchange ratio of 0.5533 shares of Zoom Class A common stock for each share of Five9 common stock, holders of shares of Five9 common stock as of immediately prior to the effective time would hold, in the aggregate, approximately (i) 13.47% of the issued and outstanding shares of Zoom Class A common stock immediately following the effective time and (ii) 11.20% of the issued and outstanding shares of Zoom Class A and Class B common stock, without giving effect to any shares of Zoom Class A common stock held by Five9 stockholders prior to the completion of the merger and disregarding stock options, restricted stock units and other equity awards or rights to acquire shares that may be issued by Zoom or Five9 pursuant to any employee stock plan. Additionally, whereas shares of Zoom Class A common stock to be issued to Five9 stockholders in connection with the merger are entitled to one vote per share, Zoom also has Class B common stock, which are entitled to 10 votes per share. No shares of Zoom Class B common stock will be issued to Five9 stockholders in connection with the merger.

Consequently, even if all former Five9 stockholders voted together on all matters presented to Zoom stockholders from time to time, the former Five9 stockholders would exercise significantly less influence over Zoom after the completion of the merger relative to their influence over Five9 prior to the completion of the merger, and thus would have a less significant impact on the approval or rejection of future Zoom proposals submitted to a stockholder vote. For additional information on the voting rights of Zoom Class A common stock and Zoom Class B common stock, please see the section entitled “Description of Zoom Capital Stock—Class A and Class B Common Stock—Voting Rights.”

The merger may not be accretive, and may be dilutive, to Zoom’s earnings per share, which may negatively affect the market price of Zoom Class A common stock.

In connection with the completion of the merger, based on the number of issued and outstanding shares of Five9 common stock as of August 6, 2021 and the number of outstanding Five9 equity awards currently estimated to be payable in Zoom Class A common stock following the merger, Zoom will issue up to approximately 43,673,988 shares of Zoom Class A common stock. The issuance of these new shares of Zoom Class A common stock could have the effect of depressing the market price of Zoom Class A common stock, through dilution of earnings per share or otherwise. Any dilution of, or delay of any accretion to, Zoom’s earnings per share could cause the price of shares of Zoom Class A common stock to decline or increase at a reduced rate.

Zoom and Five9 will incur significant transaction and merger-related costs in connection with the merger, which may be in excess of those anticipated by Zoom or Five9.

Each of Zoom and Five9 has incurred and expects to continue to incur a number of non-recurring costs associated with negotiating and completing the merger, combining the operations of the two companies and achieving desired synergies. These fees and costs have been, and will continue to be, substantial. The substantial majority of non-recurring expenses will consist of transaction costs related to the merger and include, among others, employee retention costs, fees paid to financial, legal and accounting advisors, severance and benefit costs, proxy solicitation costs and filing fees.

Zoom and Five9 will also incur transaction fees and costs related to formulating and implementing integration plans, including facilities and systems consolidation costs and employment-related costs. Zoom and

-29-

Five9 will continue to assess the magnitude of these costs, and additional unanticipated costs may be incurred in the merger and the integration of the two companies’ businesses. Although Zoom and Five9 each expect that the elimination of duplicative costs, as well as the realization of other efficiencies related to the integration of the businesses, should allow Zoom and Five9 to offset integration-related costs over time, this net benefit may not be achieved in the near term, or at all. For additional information, see the risk factor entitled “—Risk Factors Relating to Zoom and the Surviving Company—The integration of Five9 into Zoom may not be as successful as anticipated” below.

The costs described above, as well as other unanticipated costs and expenses, could have a material adverse effect on the financial condition and operating results of Zoom following the completion of the merger.

Many of these costs will be borne by Zoom or Five9 even if the merger is not completed.

Litigation relating to the merger, if any, could result in an injunction preventing the completion of the merger and/or substantial costs to Zoom and Five9.

Securities class action lawsuits and derivative lawsuits are often brought against public companies that have entered into acquisition, merger or other business combination agreements like the merger agreement. Even if such a lawsuit is without merit, defending against these claims can result in substantial costs and divert management time and resources. An adverse judgment could result in monetary damages, which could have a negative impact on Zoom’s and Five9’s respective liquidity and financial condition. Lawsuits that may be brought against Zoom, Five9 or their respective directors could also seek, among other things, injunctive relief or other equitable relief, including a request to rescind parts of the merger agreement already implemented and to otherwise enjoin the parties from consummating the merger. One of the conditions to the closing of the merger is that no injunction by any governmental entity having jurisdiction over Zoom, Five9 or Merger Sub has been entered and continues to be in effect and no law has been adopted, in either case, that prohibits the closing of the merger. Consequently, if a plaintiff is successful in obtaining an injunction prohibiting completion of the merger, that injunction may delay or prevent the merger from being completed within the expected time frame or at all, which may adversely affect Zoom’s and Five9’s respective business, financial position and results of operations.

There can be no assurance that any of the defendants will be successful in the outcome of any potential future lawsuits. The defense or settlement of any lawsuit or claim that remains unresolved at the time the merger is completed may adversely affect Zoom’s or Five9’s business, financial condition, results of operations and cash flows.

The selected unaudited pro forma condensed combined financial information in this proxy statement/prospectus is presented for illustrative purposes only and may not be reflective of the operating results and financial condition of Zoom following completion of the merger.

The unaudited pro forma condensed combined financial information in this proxy statement/prospectus is presented for illustrative purposes only and is not necessarily indicative of what Zoom’s actual financial position or results of operations would have been had the merger been completed on the dates indicated. The unaudited pro forma condensed combined financial information is subject to a number of assumptions, and does not take into account any synergies related to the merger. Further, Zoom’s actual results and financial position after the merger may differ materially and adversely from the unaudited pro forma condensed combined financial data that are included in this proxy statement/prospectus. The unaudited pro forma condensed combined financial information reflects adjustments based upon preliminary estimates of the fair value of assets to be acquired and liabilities to be assumed. The final acquisition accounting will be based upon the actual consideration transferred and the fair value of the assets and liabilities of Five9 as of the date of the completion of the merger. Accordingly, the final acquisition accounting may differ materially from the unaudited pro forma condensed combined financial information reflected in this proxy statement/prospectus. For further discussion, see the section entitled “Selected Unaudited Pro Forma Condensed Combined Financial Data.”

-30-

The opinion of Five9’s financial advisor will not reflect changes in circumstances between the signing of the merger agreement and the completion of the merger.

Five9 has received an opinion from Qatalyst Partners in connection with the signing of the merger agreement, but has not obtained an updated opinion from Qatalyst Partners as of the date of this proxy statement/prospectus. Changes in the operations and prospects of Zoom or Five9, general market and economic conditions and other factors that may be beyond the control of Zoom or Five9, and on which Five9’s financial advisor’s opinion was based, may significantly alter the value of Zoom or Five9 or the prices of the shares of Zoom Class A common stock or of the shares of Five9 common stock by the time the merger is completed. The opinion does not speak as of the time the merger will be completed or as of any date other than the date of such opinion. Because Five9 does not currently anticipate asking its financial advisor to update its opinion, the opinion will not address the fairness of the merger consideration or the exchange ratio, as applicable, from a financial point of view at the time the merger is completed. The Five9 board’s recommendation that Five9 stockholders vote “FOR” approval of the merger proposal, the non-binding compensation advisory proposal and the adjournment proposal, however, is made as of the date of this proxy statement/prospectus.

For a description of the opinion that Five9 received from its financial advisor, see the section entitled “The Merger—Opinion of Five9’s Financial Advisor.” A copy of the opinion of Qatalyst Partners, Five9’s financial advisor, is attached as Annex B to this proxy statement/prospectus and is incorporated by reference herein in its entirety.

Each party is subject to business uncertainties and contractual restrictions while the merger is pending, which could adversely affect each party’s business and operations.

In connection with the pendency of the merger, it is possible that some customers, suppliers, strategic partners and other persons with whom Zoom and/or Five9 have a business relationship may delay or defer certain business decisions or might decide to seek to terminate, change or renegotiate their relationships with Zoom or Five9, as the case may be, as a result of the merger or otherwise, which could negatively affect Zoom’s or Five9’s respective revenues, earnings and/or cash flows, as well as the market price of Zoom Class A common stock or Five9 common stock, regardless of whether the merger is completed.

Until the merger is completed, the merger agreement restricts each of Zoom and Five9 from taking specified actions without the consent of the other party, and requires Five9 to use reasonable best efforts to conduct its business in all material respects in the ordinary course of business consistent with past practice. Zoom and Five9 are subject to a number of interim operating covenants relating to, among other things, amendment of organizational documents, payment of dividends or entry into certain acquisitions or investments. Such limitations could adversely affect each of Zoom’s and Five9’s business and operations prior to the completion of the merger.

Each of the risks described above may be exacerbated by delays or other adverse developments with respect to the completion of the merger. For further discussion, see the section entitled “The Merger Agreement—Conduct of Business Before Completion of the Merger.”

The merger agreement limits Five9’s ability to pursue alternatives to the merger, may discourage certain other companies from making favorable alternative transaction proposals and, in specified circumstances, could require Five9 to pay Zoom a termination fee.

The merger agreement contains provisions that may discourage a third party from submitting an acquisition proposal to Five9 that might result in greater value to Five9’s stockholders than the merger, or may result in a potential competing acquirer of Five9 proposing to pay a lower per share price to acquire Five9 than it might otherwise have proposed to pay. These provisions include a general prohibition on Five9 from soliciting or, subject to certain exceptions relating to the exercise of fiduciary duties by the Five9 board, entering into

-31-

discussions with any third party regarding any acquisition proposal for Five9 or offer for a competing transaction. Further, even if the Five9 board withholds, withdraws, qualifies or modifies its recommendation with respect to the merger proposal, unless the merger agreement has been terminated in accordance with its terms, Five9 will still have an obligation to submit the merger proposal to a vote by its stockholders. The merger agreement further provides that under specified circumstances, including after a change of recommendation by the Five9 board and a subsequent termination of the merger agreement by the other party in accordance with its terms, Five9 may be required to pay Zoom a cash termination fee of $450 million. For additional information, see the sections entitled “The Merger Agreement—No Solicitation of Other Offers by Five9,” “The Merger Agreement—Change of Recommendation; Match Rights” and “The Merger Agreement—Termination of the Merger Agreement.”

The merger may not be completed and the merger agreement may be terminated in accordance with its terms.

The completion of the merger is subject to a number of conditions that must be satisfied or waived prior to the closing, which are described in the section entitled “The Merger Agreement—Conditions to the Merger.” These conditions to the closing may not be satisfied or waived in a timely manner or at all, and, accordingly, the merger may be delayed or may not be completed.

If the merger is not completed by January 16, 2022 (subject to two extensions of three months each in order to obtain required regulatory (including telecommunications-related) approvals and one additional extension of three months in order to obtain certain required regulatory telecommunications-related approvals), either Zoom or Five9 may choose not to proceed with the merger by terminating the merger agreement. The merger agreement may also be terminated if the other conditions to closing are not satisfied, and Zoom and Five9 may also mutually decide to terminate the merger agreement at any time prior to the effective time. For further details, see the section entitled “The Merger Agreement—Termination of the Merger Agreement.”

Failure to complete the merger could negatively impact the price of shares of Zoom Class A common stock and the price of shares of Five9 common stock, as well as Zoom’s and Five9’s respective future businesses and financial results.

The merger agreement contains a number of conditions that must be satisfied or waived prior to the completion of the merger, which are described in the section entitled “The Merger Agreement—Conditions to the Merger.” There can be no assurance that all of the conditions to the merger will be so satisfied or waived. If these conditions are not satisfied or waived, Zoom and Five9 will be unable to complete the merger.

If the merger is not completed for any reason, including the failure to receive the Five9 stockholder approval, or is completed on different terms than as contemplated by the merger agreement, Zoom’s and Five9’s respective businesses and financial results may be adversely affected, including as follows:

-32-

In addition to the above risks, if the merger agreement is terminated and either party’s board seeks an alternative transaction, such party’s stockholders cannot be certain that such party will be able to find a party willing to engage in a transaction on more attractive terms than the merger.

Completion of the merger may trigger change-in-control or other provisions in certain agreements to which Five9 is a party.

The completion of the merger may trigger change-in-control or other provisions in certain agreements to which Five9 is a party. If Zoom and Five9 are unable to negotiate waivers of those provisions, the counterparties may exercise their rights and remedies under the agreements, potentially terminating the agreements or seeking monetary damages. Even if Zoom and Five9 are able to negotiate waivers, the counterparties may require a fee for such waivers or seek to renegotiate the agreements on terms less favorable to Five9.

Holders of Five9 common stock will not be entitled to appraisal rights in the merger.

Section 262 of the DGCL provides that stockholders have the right, in some circumstances, to dissent from certain corporate actions and to instead demand payment of the fair value of their shares. Stockholders do not have appraisal rights with respect to shares of any class or series of stock if such shares of stock, or depositary receipts in respect thereof, are either (a) listed on a national securities exchange or (b) held of record by more than 2,000 holders, unless the stockholders receive in exchange for their shares anything other than shares of stock of the surviving or resulting corporation (or depositary receipts in respect thereof), or of any other corporation that is publicly listed or held by more than 2,000 holders of record, cash in lieu of fractional shares or fractional depositary receipts described above or any combination of the foregoing.

Therefore, because shares of Zoom Class A common stock are listed on Nasdaq, and the transaction consideration consists of only shares of Zoom Class A common stock, which are listed on Nasdaq, and cash in lieu of fractional shares, holders of Five9 common stock are not entitled to appraisal rights in the offer or the merger with respect to their shares of Five9 common stock. See the section entitled “No Appraisal Rights.”

If the merger does not qualify as a “reorganization” under Section 368(a) of the Code, U.S. holders of Five9 common stock may be required to pay additional U.S. federal income taxes.

The merger is intended to qualify as a “reorganization” within the meaning of Section 368(a) of the Code. It is a condition to the completion of the merger that each of Five9 and Zoom receives an opinion from counsel, dated as of the closing date, to the effect that the merger will qualify as a “reorganization” within the meaning of Section 368(a) of the Code. In addition, in connection with the filing of the registration statement of which this proxy statement/prospectus is a part, each of Latham & Watkins LLP and Cooley LLP has delivered an opinion to Five9 and Zoom, respectively, to the same effect as the opinions described in the preceding sentence. Each such opinion will be or is based on, among other things, certain facts and representations, each made by officers of Five9 and Zoom, and assumptions, all of which must be consistent with the state of facts existing at the time of the merger. If any of these facts, representations and assumptions are, or become, inaccurate or incomplete, such opinions may be invalid, and the conclusions reached therein could be jeopardized. An opinion of counsel represents counsel’s best legal judgment and is not binding on the IRS or the courts, which may not agree with the conclusions set forth in such opinions.

No ruling has been, or will be, sought by Five9 or Zoom from the IRS with respect to the merger and there can be no assurance that the IRS will not challenge the qualification of the merger as a “reorganization” under Section 368(a) of the Code or that a court would not sustain such a challenge. If the IRS successfully challenges the reorganization status of the merger, U.S. holders will be treated as if they sold their Five9 common stock in a fully taxable transaction.

For additional information, see the section entitled “Material U.S. Federal Income Tax Consequences of the Merger.” The tax consequences to you of the merger will depend on your particular facts and circumstances.

-33-

Please consult your own tax advisor as to the tax consequences of the merger in your particular circumstances, including the applicability and effect of U.S. federal, state, local and foreign income and other tax laws.

Risk Factors Relating to Zoom and the Surviving Company

The integration of Five9 into Zoom may not be as successful as anticipated.

The merger involves numerous operational, strategic, financial, accounting, legal, tax and other risks, potential liabilities associated with the acquired businesses, and uncertainties related to design, operation and integration of Five9’s internal control over financial reporting. Difficulties in integrating Five9 into Zoom may result in Five9 performing differently than expected, in operational challenges or in the failure to realize anticipated expense-related efficiencies. Zoom’s and Five9’s existing businesses could also be negatively impacted by the merger. Potential difficulties that may be encountered in the integration process include, among other factors:

Zoom may fail to realize all of the anticipated benefits of the merger or those benefits may take longer to realize than expected.

Zoom believes that there are significant benefits and synergies that may be realized through leveraging the products, scale and combined enterprise customer bases of Zoom and Five9. However, the efforts to realize these benefits and synergies will be a complex process and may disrupt both companies’ existing operations if not implemented in a timely and efficient manner. The full benefits of the transactions contemplated by the merger agreement, including the anticipated sales or growth opportunities, may not be realized as expected or may not be achieved within the anticipated time frame, or at all. Failure to achieve the anticipated benefits of the merger could adversely affect Zoom’s results of operations or cash flows, cause dilution to the earnings per share of Zoom, decrease or delay any accretive effect of the merger and negatively impact the price of Zoom Class A common stock.

Following completion of the merger, Zoom’s success will depend, in part, on its ability to manage its expansion, which poses numerous risks and uncertainties, including the need to integrate the operations and business of Five9 into its existing business in an efficient and timely manner, to combine systems and management controls and to integrate relationships with industry contacts and business partners. In addition, Zoom will need to manage the international operations of Five9, including engineering personnel and operations in Russia, which may pose regulatory, economic and political risks as well as additional challenges if the relationship between Russia and the United States worsens significantly, or if either Russia or the United States

-34-

imposes or implements new or augmented economic sanctions, supply chain restrictions or other restrictions on doing business. For example, in recent years, the U.S. Government has expressed concerns with the security of information and communications technology and services (which we refer to as “ICTS”) sourced from providers in China, Russia, and other jurisdictions. On March 22, 2021, the U.S. Department of Commerce issued an interim final rule allowing it to identify, review, and prohibit ICTS transactions that pose a national security risk, including transactions from specified countries, including Russia. Several aspects of the rule remain uncertain, including the scope of affected transactions and how the rule will be implemented and enforced in practice. This rule could potentially impact Five9’s business and the ability to offer Five9 products and services in certain circumstances.

In addition, Zoom and Five9 will be required to devote significant attention and resources prior to closing to prepare for the post-closing integration and operation of the surviving company, and Zoom will be required post-closing to devote significant attention and resources to successfully align the business practices and operations of Zoom and Five9. This process may disrupt the businesses and, if ineffective, would limit the anticipated benefits of the merger.

Zoom and Five9 will incur direct and indirect costs as a result of the merger.

Zoom and Five9 will incur substantial expenses in connection with and as a result of completing the merger, and, following the completion of the merger, Zoom expects to incur additional expenses in connection with combining the businesses and operations of Zoom and Five9. Factors beyond Zoom’s control could affect the total amount or timing of these expenses, many of which, by their nature, are difficult to estimate accurately. Moreover, diversion of management focus and resources from the day-to-day operation of the business to matters relating to the transactions could adversely affect each company’s business, regardless of whether the merger is completed.

Uncertainties associated with the merger may cause a loss of management personnel and other key employees, which could adversely affect the future business and operations of the combined company.

Zoom and Five9 are dependent on the experience and industry knowledge of their officers and other key employees to execute their business plans. Each company’s success until the merger and the surviving company’s success after the merger will depend in part upon the ability of Zoom and Five9 to retain key management personnel and other key employees. Current and prospective employees of Zoom and Five9 may experience uncertainty about their roles within the combined company following the merger, which may have an adverse effect on the ability of each of Zoom and Five9 to attract or retain key management and other key personnel. Accordingly, no assurance can be given that the combined company will be able to attract or retain key management personnel and other key employees of Zoom and Five9 to the same extent that Zoom and Five9 have previously been able to attract or retain their own employees.

Sales of substantial amounts of Zoom shares in the open market by former Five9 stockholders could depress its stock price.

Other than shares held by persons who will be affiliates of Zoom after the closing, shares of Zoom Class A common stock that are issued to Five9 stockholders, including those shares issued upon the exercise of outstanding stock options or restricted stock units, will be freely tradable without restrictions or further registration under the Securities Act. If the merger is completed and if former Five9 stockholders and Five9 employees sell substantial amounts of Zoom Class A common stock in the public market following consummation of the merger, the market price of Zoom Class A common stock may decrease.

Zoom’s and Five9’s business relationships may be subject to disruption due to uncertainty associated with the merger.

Parties with which Zoom or Five9 do business may experience uncertainty associated with the merger, including with respect to current or future business relationships with Zoom or Five9. Zoom’s and Five9’s

-35-

business relationships may be subject to disruption as parties with which Zoom or Five9 do business may attempt to negotiate changes in existing business relationships or consider entering into business relationships with parties other than Zoom or Five9. These disruptions could have an adverse effect on the businesses, financial condition, results of operations or prospects of each company, including an adverse effect on Zoom’s ability to realize the anticipated benefits of the merger. The risk, and adverse effect, of such disruptions could be exacerbated by a delay in completion of the merger or termination of the merger agreement.

Risks Related to Zoom’s Business

You should read and consider the risk factors specific to Zoom’s business that will also affect the surviving company after the closing. These risks are described in Zoom’s Annual Report on Form 10-K for the fiscal year ended January 31, 2021 and its Quarterly Report on Form 10-Q for the quarterly period ended April 30, 2021, which are incorporated by reference into this document, and in other documents that are incorporated by reference into this document. For additional information, see the section entitled “Where You Can Find More Information.”

Risks Related to Five9’s Business

You should read and consider the risk factors specific to Five9’s business that will also affect the surviving company after the closing. These risks are described in Five9’s Annual Report on Form 10-K for the year ended December 31, 2020 and its Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2021, which are incorporated by reference into this document, and in other documents that are incorporated by reference into this document. For additional information, see the section entitled “Where You Can Find More Information.”

-36-

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS

This proxy statement/prospectus, and the documents to which Zoom and Five9 refer you in this proxy statement/prospectus, as well as oral statements made or to be made by Zoom and Five9, may include certain “forward-looking statements” within the meaning of Section 27A of the Securities Act and Section 21E of the Exchange Act. Forward-looking statements relate to future events and anticipated results of operations and business strategies, statements regarding the merger, including the anticipated benefits of the merger, the anticipated impact of the merger on the combined company’s business and future financial and operating results, the expected amount and timing of synergies from the merger, and the anticipated closing date for the proposed transaction and other aspects of operations or operating results. These forward-looking statements generally can be identified by phrases such as “will,” “expects,” “anticipates,” “foresees,” “forecasts,” “estimates” or other words or phrases of similar import. It is uncertain whether any of the events anticipated by the forward-looking statements will transpire or occur, or if any of them do, what impact they will have on the results of operations and financial condition of the combined company or the price of Zoom or Five9 stock. These forward-looking statements involve certain risks and uncertainties, many of which are beyond the parties’ control, that could cause actual results to differ materially from those indicated in such forward-looking statements, including but not limited to:

-37-

All of the forward-looking statements Zoom and Five9 make in this proxy statement/prospectus are qualified by the information contained or incorporated by reference herein, including the information contained in this section and the information detailed in Zoom’s Annual Report on Form 10-K for the fiscal year ended January 31, 2021 and Zoom’s Quarterly Report on Form 10-Q for the quarterly period ended April 30, 2021, Current Reports on Form 8-K and other filings Zoom makes with the SEC, which are incorporated herein by reference, and in Five9’s Annual Report on Form 10-K for the fiscal year ended December 31, 2020 and Five9’s Quarterly Reports on Form 10-Q for the quarterly periods ended March 31, 2021 and June 30, 2021, Current Reports on Form 8-K and other filings Five9 makes with the SEC, which are incorporated herein by reference. For additional information, see the sections entitled “Risk Factors” and “Where You Can Find More Information.”

Except as required by law, neither Zoom nor Five9 undertakes or assumes any obligation to update any forward-looking statements, whether as a result of new information or to reflect subsequent events or circumstances or otherwise. Readers are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof.

-38-

INFORMATION ABOUT THE COMPANIES

Zoom

Zoom Video Communications, Inc.

55 Almaden Boulevard, 6th Floor

San Jose, California 95113

Phone: (888) 799-9666

Zoom’s mission is to make video communications frictionless and secure.

Zoom provides a video-first unified communications platform that delivers happiness and fundamentally changes how people interact. Zoom connects people through frictionless and secure video, phone, chat, and content sharing and enable face-to-face video experiences for thousands of people in a single meeting across disparate devices and locations. Zoom’s cloud-native platform delivers reliable, high-quality video and voice that is easy to use, manage, and deploy; provides an attractive return on investment; is scalable and easily integrates with physical spaces and applications. Zoom believes that rich and reliable communications lead to interactions that build greater empathy and trust. Zoom strives to live up to the trust our customers place in it by delivering a communications solution that “just works.”

Zoom Class A common stock is traded on Nasdaq under the ticker symbol “ZM.”

Merger Sub

Summer Merger Sub, Inc.

c/o Zoom Video Communications, Inc.

55 Almaden Boulevard, 6th Floor

San Jose, California 95113

Phone: (888) 799-9666

Merger Sub, a Delaware corporation, is a wholly owned subsidiary of Zoom. Merger Sub is newly formed, and was organized for the purpose of entering into the merger agreement and effecting the merger. Merger Sub has engaged in no business activities to date and it has no material assets or liabilities of any kind, other than those incident to its formation and those incurred in connection with the merger.

Five9

Five9, Inc.

3001 Bishop Drive, Suite 350

San Ramon, California 94583

Phone: (925) 201-2000

Five9 is a pioneer and leading provider of intelligent cloud software for contact centers. Five9 was “born in the cloud,” and since its inception, Five9 has exclusively focused on delivering its platform in the cloud and is disrupting a significantly large market by replacing legacy on-premise contact center systems. Contact centers are vital hubs of interaction between organizations and their customers and, therefore, are essential to delivering successful customer service, sales and marketing strategies. Five9’s mission is to empower organizations to transform their contact centers into customer engagement centers of excellence, while improving business agility and significantly lowering the cost and complexity of their contact center operations. Five9’s purpose-built, highly scalable and secure Virtual Contact Center, or VCC, cloud platform delivers a comprehensive suite of easy-to-use applications that enable the breadth of contact center-related customer service, sales and marketing

-39-

functions. Five9 has become an established leader in the cloud contact center market, facilitating more than seven billion call minutes between its more than 2,000 clients and their customers per year. Five9 believes its ability to combine software and telephony into a single unified platform that is delivered in the cloud creates a significant advantage.

Five9 common stock is traded on Nasdaq under the ticker symbol “FIVN.”

-40-

SPECIAL MEETING OF FIVE9 STOCKHOLDERS

Date, Time and Place

The Five9 special meeting will be held virtually via the Internet on                , 2021 at                , Pacific Time. The Five9 special meeting will be held solely via live webcast and there will not be a physical meeting location. Five9 stockholders will be able to attend the Five9 special meeting online and vote their shares electronically during the meeting by visiting the Five9 special meeting website at                 . Five9 stockholders will need the 16-digit control number found on their proxy card in order to access the Five9 special meeting website.

Purpose of the Five9 Special Meeting

The purpose of the Five9 special meeting is to consider and vote on:

Five9 will transact no other business at the Five9 special meeting.

Recommendation of the Five9 Board

The Five9 board unanimously recommends that Five9 stockholders vote:

For additional information on the recommendation of the Five9 board, see the section entitled “The Merger—Reasons for the Merger—Recommendation of the Five9 Board and Reasons for the Merger.”

Record Date and Outstanding Shares of Five9 Common Stock

Only holders of record of issued and outstanding shares of either class of Five9 common stock as of the close of business on                , 2021, the record date for the Five9 special meeting, are entitled to notice of, and to vote at, the Five9 special meeting via the Five9 special meeting website or any adjournment or postponement of the Five9 special meeting.

As of the close of business on the record date, there were                 shares of Five9 common stock outstanding and entitled to vote at the Five9 special meeting. Each share of common stock is entitled to one vote on each proposal.

A complete list of Five9 stockholders entitled to vote at the Five9 special meeting will be available for inspection at Five9’s principal place of business during regular business hours for a period of no less than 10 days before the Five9 special meeting at 3001 Bishop Drive, Suite 350, San Ramon, California 94583. If Five9’s headquarters are closed for health and safety reasons related to the COVID-19 pandemic during such period, the list of Five9 stockholders will be made available for inspection upon request to Five9’s Investor Relations department at ir@five9.com, subject to the satisfactory verification of stockholder status. The list of Five9 stockholders entitled to vote at the Five9 special meeting will also be made available for inspection during the Five9 special meeting via the Five9 special meeting website at                 .

-41-

Quorum; Abstentions and Broker Non-Votes

A quorum of Five9 stockholders is necessary to hold a valid meeting. The presence at the Five9 special meeting, in person (including via the Five9 special meeting website) or by proxy, of the holders of a majority of the voting power of all issued and outstanding shares of Five9 common stock entitled to vote at the Five9 special meeting constitutes a quorum. Abstentions, withhold votes, and broker non-votes are counted as shares present and entitled to vote for the purposes of determining a quorum.

Required Vote

Approval of the merger proposal requires the affirmative vote of a majority of the voting power of all issued and outstanding shares of Five9 common stock as of the close of business on the record date and entitled to vote on the proposal. Abstentions and broker non-votes will have the same effect as a vote “AGAINST” the proposal. Failure to vote on the merger proposal will have the same effect as a vote “AGAINST” the merger proposal.

Approval of the non-binding compensation advisory proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote.

Approval of the adjournment proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote.

The merger proposal, the non-binding compensation advisory proposal and the adjournment proposal are described in the section entitled “Five9 Proposals.”

Methods of Voting

Five9 stockholders of record may vote their shares in four ways:

In order to be counted, proxies submitted by telephone or Internet must be received by 11:59 p.m. Eastern Time on                , 2021. Proxies submitted by U.S. mail must be received before the start of the Five9 special meeting.

If you are a street name stockholder, please follow the instructions from your broker, bank, or other nominee set forth on your enclosed voting instruction form for how to vote.

Voting via the Five9 Special Meeting Website

Shares held directly in your name as stockholder of record may be voted at the Five9 special meeting via the Five9 special meeting website. If you choose to virtually attend the Five9 special meeting website and vote your

-42-

shares at the meeting via the Five9 special meeting website, you will need the 16-digit control number included on your proxy card.

If you are a beneficial holder, you will need to obtain a specific control number from your broker, bank or other nominee holder of record giving you the right to vote the shares and you will need to provide a “legal proxy” from your broker, bank or other nominee holder of record in order to vote your shares at the Five9 special meeting.

Even if you plan to virtually attend the Five9 special meeting, the Five9 board recommends that you vote your shares in advance as described below so that your vote will be counted if you later decide not to attend the Five9 special meeting.

Voting by Proxy

You may direct your vote by proxy without virtually attending the Five9 special meeting. You can vote by proxy by phone, the Internet or mail by following the instructions provided in the enclosed proxy card. If you are a street name stockholder, please follow the instructions from your broker, bank, or other nominee as set forth on your enclosed voting instructions form for how to vote.

Questions About Voting

If you have any questions about how to vote or direct a vote in respect of your shares of Five9 common stock, you may contact Innisfree, Five9’s proxy solicitor, toll-free at (877) 750-8197, or for brokers and banks, collect at (212) 750-5833.

Adjournment

In accordance with the Five9 bylaws, whether or not a quorum is present, the chairman of the Five9 special meeting will have the power to adjourn the Five9 special meeting from time to time, without notice unless the adjournment is for more than thirty days. If the Five9 special meeting is adjourned, Five9 stockholders who have already submitted their proxies will be able to revoke them at any time prior to their use. At any subsequent reconvening of the Five9 special meeting, all proxies will be voted in the same manner as the manner in which such proxies would have been voted at the original convening of the Five9 special meeting, except for any proxies that have been validly revoked or withdrawn prior to the subsequent meeting.

In addition, the merger agreement provides that Five9 may adjourn or postpone the Five9 special meeting (i) after consultation with Zoom, to the extent necessary to ensure that any supplement or amendment to this proxy statement/prospectus that is required by applicable law is provided to the Five9 stockholders within a reasonable amount of time in advance of the Five9 special meeting or (ii) if, as of the time the Five9 special meeting is scheduled, there are not sufficient affirmative votes in person or proxy at the Five9 special meeting to constitute a quorum or to obtain the approval of the merger proposal; provided that Five9 will only be permitted to effect one such adjournment or postponement under the circumstances described in clause (ii). If requested by Zoom under the circumstances described in clause (ii), Five9 will be required to adjourn or postpone the special meeting once for two periods of up to 20 business days in the aggregate. However, the Five9 special meeting will not be adjourned or postponed if it would require a change in the record date.

Revocability of Proxies

If you are a stockholder of record, you can change your vote or revoke your proxy before your proxy is exercised at the Five9 special meeting as described herein. You may do this in one of the following four ways:

-43-

In light of restrictions currently in place due to COVID-19, stockholders are encouraged to change their vote by voting again using the telephone or Internet.

If you are a street name stockholder, you may revoke any prior voting instructions by contacting your broker, bank or other nominee or by attending the Five9 special meeting and voting by Internet during the meeting. Note that if you are a street name stockholder, you will need to provide a “legal proxy” from your broker, bank or other nominee in order to vote by Internet during the Five9 special meeting.

Proxy Solicitation Costs

The enclosed proxy card is being solicited by Five9 and the Five9 board. In addition to solicitation by mail, Five9’s directors, officers and employees may solicit proxies in person, by phone or by electronic means. These persons will not be specifically compensated for conducting such solicitation.

Five9 has retained Innisfree to assist in the solicitation process. Five9 estimates that it will pay Innisfree a fee of approximately $45,000, as well as reasonable and customary documented expenses. Five9 also has agreed to indemnify Innisfree against various liabilities and expenses that relate to or arise out of its solicitation of proxies (subject to certain exceptions).

Five9 will ask brokers, banks and other nominees to forward the proxy solicitation materials to the beneficial owners of shares of Five9 common stock held of record by such nominee holders. Five9 will reimburse these nominee holders for their customary clerical and mailing expenses incurred in forwarding the proxy solicitation materials to the beneficial owners.

No Appraisal Rights

Stockholders are not entitled to appraisal rights under Delaware law in connection with the merger transaction. See the section entitled “No Appraisal Rights.”

Other Information

The matters to be considered at the Five9 special meeting are of great importance to the Five9 stockholders. Accordingly, you are urged to read and carefully consider the information contained in or incorporated by reference into this proxy statement/prospectus and submit your proxy by phone or the Internet or complete, date, sign and promptly return the enclosed proxy card in the postage-paid envelope provided. If you submit your proxy by phone or the Internet, you do not need to return the enclosed proxy card by mail.

-44-

Assistance

If you need assistance in completing your proxy card or have questions regarding the Five9 special meeting, contact:

Innisfree M&A Incorporated

501 Madison Avenue, 20^th Floor

New York, New York 10022

(877) 750-8197

Banks and Brokers: (212) 750-5833

Vote of Five9’s Directors and Executive Officers

As of August 6, 2021, Five9 directors, executive officers, and their respective affiliates, as a group, beneficially held and were entitled to vote 428,064 shares of Five9 common stock, representing 0.63% of the voting power of Five9 common stock.

Five9 currently expects that all of its directors and executive officers will vote their shares “FOR” the merger proposal, “FOR” the non-binding compensation advisory proposal and “FOR” the adjournment proposal although none of the Five9 directors or officers has entered into any agreement to do so.

Attending the Five9 Special Meeting Virtually

You are entitled to attend the Five9 special meeting only if you were a stockholder of record of Five9 at the close of business on the record date or you held your shares of Five9 beneficially in the name of a broker, bank or other nominee as of the record date, or you hold a valid proxy for the Five9 special meeting.

If you were a stockholder of record of Five9 at the close of business on the record date and wish to attend the Five9 special meeting, you will need the 16-digit control number located on your proxy card.

If a broker, bank or other nominee is the record owner of your shares of Five9 common stock, you will need to obtain your specific control number and further instructions from your bank, broker or other nominee.

Results of the Five9 Special Meeting

Within four business days following the Five9 special meeting, Five9 intends to file the final voting results with the SEC on a Current Report on Form 8-K. If the final voting results have not been certified within that four-business day period, Five9 will report the preliminary voting results on a Current Report on Form 8-K at that time and will file an amendment to the Current Report on Form 8-K to report the final voting results within four days of the date that the final results are certified.

FIVE9 STOCKHOLDERS SHOULD CAREFULLY READ THIS PROXY STATEMENT/PROSPECTUS IN ITS ENTIRETY FOR MORE DETAILED INFORMATION CONCERNING THE MERGER PROPOSAL, THE NON-BINDING COMPENSATION ADVISORY PROPOSAL AND THE ADJOURNMENT PROPOSAL.

-45-

FIVE9 PROPOSALS

Merger Proposal

It is a condition to the completion of the merger that Five9 stockholders approve the merger proposal. In the merger, each Five9 stockholder will receive, for each eligible share of Five9 common stock that is issued and outstanding as of immediately prior to the effective time, the merger consideration of 0.5533 shares of Zoom Class A common stock, without interest, further described in the sections entitled “The Merger—Consideration to Five9 Stockholders” and “The Merger Agreement—Merger Consideration.”

The approval by such stockholders of this proposal is required by Section 251 of the DGCL and is a condition to the completion of the merger.

Approval of the merger proposal requires the affirmative vote of a majority of the voting power of all issued and outstanding shares of Five9 common stock as of the close of business on the record date and entitled to vote on the proposal. Abstentions and broker non-votes will have the same effect as a vote “AGAINST” the merger proposal. Failure to vote on the merger proposal will have the same effect as a vote “AGAINST” the merger proposal.

The Five9 board unanimously recommends a vote “FOR” the merger proposal.

Non-Binding Compensation Advisory Proposal

As required by Section 14A of the Exchange Act and the applicable SEC rules issued thereunder, which were enacted pursuant to the Dodd-Frank Wall Street Reform and Consumer Protection Act, Five9 is required to provide its stockholders the opportunity to vote to approve, on a non-binding, advisory basis, certain compensation that may be paid or become payable to Five9’s named executive officers that is based on or otherwise relates to the merger, as described in the section entitled “The Merger—Interests of Five9 Directors and Executive Officers in the Merger.” Accordingly, Five9 stockholders are being provided the opportunity to cast an advisory vote on such payments.

As an advisory vote, this proposal is not binding upon Five9 or the Five9 board or Zoom or the Zoom board, and approval of this proposal is not a condition to completion of the merger and is a vote separate and apart from the merger proposal. Accordingly, you may vote to approve the merger proposal and vote not to approve the non-binding compensation advisory proposal and vice versa. Because the merger-related executive compensation to be paid in connection with the merger is based on the terms of the merger agreement as well as the contractual arrangements with Five9’s named executive officers, such compensation will be payable, regardless of the outcome of this advisory vote, if the merger proposal is approved (subject only to the contractual conditions applicable thereto). However, Five9 seeks the support of its stockholders and believes that stockholder support is appropriate as the executive compensation programs are designed to incentivize executives to successfully execute a transaction such as that contemplated by the merger proposal from its early stages until consummation. Accordingly, holders of shares of Five9 common stock are being asked to vote on the following resolution:

RESOLVED, that the stockholders of Five9, Inc. approve, on an advisory, non-binding basis, certain compensation that may be paid or become payable to the named executive officers of Five9, Inc. that is based on or otherwise relates to the merger, as disclosed pursuant to Item 402(t) of Regulation S-K under the section entitled “The Merger—Interests of Five9 Directors and Executive Officers in the Merger.”

Approval of the non-binding compensation advisory proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote.

-46-

The Five9 board unanimously recommends a vote “FOR” the non-binding compensation advisory proposal.

Adjournment Proposal

The Five9 special meeting may be adjourned to another time and place to permit further solicitation of proxies, if necessary or appropriate, to obtain additional proxies if there are not sufficient votes to approve the merger proposal.

The Five9 stockholders are being asked to authorize the holder of any proxy solicited by the Five9 board to vote in favor of any adjournment of the Five9 special meeting to a later date or dates, if necessary or appropriate, to solicit additional proxies in the event there are not sufficient votes at the time of the Five9 special meeting to approve the merger proposal. Five9 does not intend to call a vote on the adjournment proposal if the merger proposal has been approved at the Five9 special meeting.

Approval of the adjournment proposal requires the affirmative vote of the holders of shares of Five9 common stock having a majority in voting power of the votes cast by the holders of shares present or represented by proxy at the Five9 special meeting and voting affirmatively or negatively on the matter. Abstentions and broker non-votes will have no effect on the outcome of the vote. If the Five9 special meeting is adjourned for the purpose of soliciting additional proxies, Five9 stockholders who have already submitted their proxies will be able to revoke them at any time prior to their use.

The adjournment proposal relates only to an adjournment of the Five9 special meeting for purposes of soliciting additional votes for approval of the merger proposal. Five9 retains full authority to the extent set forth in the Five9 bylaws and Delaware law to adjourn the Five9 special meeting for any other purpose, or to postpone the Five9 special meeting before it is convened, without the consent of any Five9 stockholder.

The Five9 board unanimously recommends a vote “FOR” the adjournment proposal.

-47-

THE MERGER

This discussion of the merger is qualified in its entirety by reference to the merger agreement, which is attached to this proxy statement/prospectus as Annex A and incorporated by reference herein in its entirety. You should read the entire merger agreement carefully as it is the legal document that governs the merger.

Transaction Structure

The merger agreement provides that, upon the terms and subject to the satisfaction or waiver of the conditions set forth in the merger agreement, and in accordance with the DGCL, Merger Sub will be merged with and into Five9 at the effective time. As a result of the merger, the separate existence of Merger Sub will cease and Five9 will continue as the surviving company and a direct, wholly owned subsidiary of Zoom.

Consideration to Five9 Stockholders

As a result of the merger, each eligible share of Five9 common stock issued and outstanding immediately prior to the effective time will be automatically cancelled and converted into the right to receive 0.5533 shares of Zoom Class A common stock, with cash in lieu of any fractional shares of Zoom Class A common stock, without interest.

Zoom will not issue fractional shares of Zoom Class A common stock in the merger. Instead, each holder of Five9 common stock who otherwise would be entitled to receive fractional shares of Zoom Class A common stock (after aggregating all shares of such holder) will be entitled to an amount in cash, without interest, equal to such fraction of a share of Zoom Class A common stock to which such holder would otherwise be entitled multiplied by Zoom trading price, rounded to the nearest whole cent.

Background of the Merger

The Five9 board, together with Five9’s senior management, regularly reviews and assesses Five9’s performance, share price, risks, opportunities and strategy in light of the current business and economic environment, as well as evolving industry dynamics, as they may affect Five9’s long-term strategic goals and plans. As a matter of practice, the Five9 board and Five9’s senior management, together with their professional advisors, regularly review and evaluate a wide range of strategic opportunities for business combinations, acquisitions and other financial and strategic alternatives for Five9, including continuing as a standalone company, with a view to maximizing stockholder value.

The Zoom board, together with members of Zoom’s management team, regularly considers and pursues opportunities to enhance Zoom’s product suite, improve customer satisfaction and unlock stockholder value. In this regard, the Zoom board and members of Zoom’s management team have reviewed and discussed business, operational and strategic plans to enhance and complement Zoom’s existing product suite in light of the current business and economic environment, as well as evolving industry dynamics. As part of Zoom’s ongoing evaluation of such opportunities, Zoom’s senior management identified Five9 as a potential candidate for a strategic transaction with Zoom.

Over the past two years, as part of Five9’s and Zoom’s existing commercial relationship, Mr. Rowan Trollope, Five9’s Chief Executive Officer, and other representatives of Five9, on the one hand, and Mr. Eric Yuan, Zoom’s Chief Executive Officer, and other representatives of Zoom, on the other hand, have had discussions from time to time to collaborate on integrating the Zoom and Five9 products to enable the use of Zoom features by Five9 customer agents, to better understand each other’s respective businesses, platforms and products and to explore various other ways in which they could collaborate in order to advance their shared business objectives.

-48-

On March 6, 2020, Mr. Yuan sent a text message to Mr. Trollope suggesting a conversation the following week to discuss a deeper, more strategic relationship between Zoom and Five9.

On March 9, 2020, Mr. Yuan and Mr. Trollope spoke, at which time Mr. Yuan raised with Mr. Trollope the idea of a combination of Five9 and Zoom. Mr. Trollope noted that if Zoom were to make a proposal for a strategic transaction with Five9, the proposal would be reviewed by the Five9 board.

During the week of March 9, 2020, Mr. Trollope updated the Five9 board and the Five9 management team regarding his discussion with Mr. Yuan and the possibility of a potential strategic transaction. During these discussions, the members of the Five9 board instructed the Five9 management team to enter into discussions with Zoom regarding a confidentiality agreement.

On March 16, 2020, the Five9 board held a regularly scheduled meeting by videoconference with representatives of Five9 senior management present at the invitation of the Five9 board. The meeting focused on an ordinary course financial update and COVID-related developments. It was noted that there had been no developments with respect to a potential strategic transaction with Zoom since Mr. Trollope’s prior update to the members of the Five9 board.

On March 19, 2020, Zoom and Five9 executed a confidentiality agreement, which included a customary mutual “standstill” provision containing a customary fallaway provision and which did not restrict Zoom from making confidential proposals to, or requesting a waiver of the standstill from, the Five9 board, to explore a potential combination.

On March 20, 2020, Mr. Yuan and Mr. Trollope exchanged text messages to schedule a meeting between their respective management teams for the following week.

On March 23, 2020, the COVID global pandemic and the related challenges had begun to consume day-to-day business priorities, and consequently Mr. Yuan and Mr. Trollope determined that it was best to pause discussions regarding a potential combination.

Over the next twelve months, representatives of Zoom and Five9 continued to engage in ordinary course discussions regarding their existing commercial relationship. However, as a result of the ongoing pandemic and other business priorities, discussions regarding a potential combination did not restart until March 2021.

On March 12, 2021, Mr. Yuan contacted Mr. Trollope to indicate that Zoom would like to resume discussions of a potential business combination with Five9.

Later that day, Mr. Trollope informed Mr. Mike Burkland, chairman of the Five9 board, of Mr. Yuan’s outreach regarding a potential business combination between Five9 and Zoom.

On March 16, 2021, Ms. Kelly Steckelberg, Zoom’s Chief Financial Officer, and Mr. Barry Zwarenstein, Five9’s Chief Financial Officer, spoke by telephone to discuss a potential strategic transaction between Zoom and Five9.

Also on March 16, 2021, Mr. Trollope contacted the other members of the Five9 board to update them on recent discussions with Mr. Yuan and Zoom, as well as discussions with potential financial advisors with respect to the proposed transaction. The members of the Five9 board indicated their support for the engagement of Qatalyst Partners LP, which we refer to as “Qatalyst Partners”, as Five9’s financial advisor given the Five9 board’s familiarity with Qatalyst Partners from its annual presentations to the Five9 board and its experience, expertise and qualifications.

Later that same day, Ms. Steckelberg updated the Zoom board regarding her discussion with Mr. Zwarenstein. After discussion over the course of the following several days, the Zoom board authorized

-49-

Zoom senior management to continue to explore a potential strategic transaction with Five9, with the Zoom transaction committee to be regularly updated and to present to the Zoom board prior to formal approval of any strategic transaction with Five9.

On March 17, 2021, Zoom and Five9 entered into a new confidentiality agreement (with an effective date of March 16, 2021), which superseded and replaced the confidentiality agreement entered into by the parties on March 19, 2020 and which included a customary mutual “standstill” provision containing a customary fallaway provision and which did not restrict Zoom from making confidential proposals to, or requesting a waiver of the standstill from, the Five9 board.

On March 19, 2021, the Five9 board held a regularly scheduled meeting by videoconference with representatives of Five9 senior management present at the invitation of the Five9 board. Among other things, Mr. Trollope provided an update to the Five9 board on discussions with Zoom and Qatalyst Partners regarding a potential business combination with Zoom. The Five9 board authorized Mr. Trollope and the other senior executives of Five9 to continue to explore Zoom’s potential interest in a potential strategic transaction with Five9, including the engagement of Qatalyst Partners to act as financial advisor to Five9 on the basis of its qualifications, expertise and reputation, its knowledge and understanding of Five9’s business, industry and affairs, and the absence of any conflicts with respect to Zoom. Ms. Kimberly Lytikainen, Five9’s General Counsel, Chief Compliance Officer and Secretary, presented to the directors proposed revisions to the charter of the Five9 M&A Committee expanding the Committee’s responsibilities from potential acquisition targets to include engagement with management on potential offers from interested parties to acquire Five9 and to oversee negotiation of proposed terms. The Five9 board unanimously approved the revised M&A Committee charter and instructed Five9’s management to engage legal counsel for the potential transaction.

Later that same day, Ms. Steckelberg reached out to Mr. Zwarenstein regarding the process for a potential business combination of Five9 and Zoom, including Five9’s preparation of a presentation for Zoom management regarding the business opportunity.

On March 19, 2021, Mr. Yuan and Mr. Trollope spoke regarding the potential strategic transaction, including regarding Mr. Trollope’s discussions with the Five9 board.

On March 21, 2021, representatives of Goldman Sachs & Co. LLC (which we refer to as “Goldman Sachs”), acting as financial advisor to Zoom, reached out to representatives of Qatalyst Partners to discuss the process for a potential strategic transaction between Five9 and Zoom.

On March 22, 2021, Five9 engaged Latham & Watkins LLP (which we refer to as “Latham & Watkins”) to act as Five9’s outside legal counsel for the potential transaction.

Also on March 22, 2021, representatives of Goldman Sachs and Qatalyst Partners discussed details of a meeting to be held between Five9’s and Zoom’s management, and representatives of Goldman Sachs requested a financial forecast for Five9. Representatives of Qatalyst Partners noted that Five9 would also need to complete reverse diligence on Zoom in order to more fully assess any proposal.

On March 24, 2021, the Five9 M&A Committee convened for a special meeting by videoconference with representatives of Five9 senior management and representatives of Qatalyst Partners and Latham & Watkins present. Representatives of Latham & Watkins reviewed the Five9 board’s fiduciary duties in connection with a potential business combination with the Five9 M&A Committee, after which the Five9 M&A Committee reviewed the potential business opportunity and the Initial Five-Year Plan, prepared by Five9 management in connection with the potential transaction with Zoom (as more fully described in the section entitled “—Projected Financial Information”). The Five9 M&A Committee approved the engagement letter with Qatalyst Partners in connection with the consideration of a potential transaction between Five9 and Zoom and later on March 24, 2021, Mr. Zwarenstein executed an engagement letter formalizing Qatalyst Partners’ engagement to act as financial advisor to the Five9 board in connection with a potential transaction.

-50-

On March 25, 2021, the Five9 board held a special meeting by videoconference with Five9 management and representatives of Latham & Watkins and Qatalyst Partners present at the invitation of the Five9 board. Representatives of Latham & Watkins and Ms. Lytikainen reviewed the Five9 board’s fiduciary duties in considering a potential transaction. Senior executives of Five9 presented updates on discussions with Zoom and the Initial Five-Year Plan, and Qatalyst Partners presented preliminary valuation considerations, discussion of the Initial Five-Year Plan and potential outreach to other potential acquirers. The Five9 board approved the use by and distribution to Zoom of the Initial Five-Year Plan in connection with the ongoing discussions regarding the transaction.

On March 26, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Zoom’s outside legal counsel, Cooley LLP, which we refer to as “Cooley”, present. Representatives of Goldman Sachs gave an overview of the status of the potential transaction with Five9, including an update from representatives of Goldman Sachs regarding trading and preliminary financial analysis.

Also on March 26, 2021, representatives of Qatalyst Partners provided representatives of Goldman Sachs with Five9’s Initial Five-Year Plan.

On March 29, 2021, representatives of Five9 senior management gave a presentation to representatives of Zoom management, which discussed Five9’s product, technology, go-to-market strategy, and Initial Five-Year Plan. Representatives of Goldman Sachs and Qatalyst Partners were in attendance.

On March 30, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Members of Zoom management gave an update on the status of the diligence performed to date. Representatives of Goldman Sachs gave an overview of the status of the potential transaction with Five9, including an update from representatives of Goldman Sachs regarding trading and preliminary financial analysis.

Throughout late March and early April, representatives of Five9 and Zoom, as well as their respective financial and legal advisors, exchanged diligence questions and responses.

On April 1, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Representatives of Goldman Sachs gave an overview of the status of the potential transaction with Five9, including an update from representatives of Goldman Sachs regarding preliminary trading and preliminary financial analysis.

On April 2, 2021, the Zoom board held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Members of Zoom management gave an overview of the strategic rationale for a potential strategic transaction with Five9, an update on the status of the diligence performed to date and presented Five9’s Initial Five-Year Plan to the Zoom board. Representatives of Goldman Sachs gave an update regarding trading and preliminary financial analysis.

On April 5, 2021, Ms. Steckelberg and Mr. Zwarenstein had a telephone meeting, requested by Ms. Steckelberg, during which Ms. Steckelberg provided Zoom’s proposal to acquire Five9 in an all-stock transaction at an exchange ratio of 0.570 shares of Zoom Class A common stock for each share of Five9 common stock (which we refer to as “Zoom’s initial offer”), which represented an implied price per share of $184.66 based on the closing trading price of Zoom Class A common stock as of April 5, 2021 and a premium of approximately 12% to the closing trading price of Five9 common stock as of April 1, 2021 (the last full day of trading prior to receipt of the offer), and Ms. Steckelberg conveyed Zoom’s desire to sign a definitive agreement by April 29, 2021.

Also on April 5, 2021, representatives of Qatalyst Partners and Goldman Sachs discussed the proposed terms of Zoom’s initial offer.

-51-

Later that same day, Mr. Trollope discussed Zoom’s initial offer with Mr. Yuan, and informed him that Mr. Trollope could not take a proposal with less than a 0.600 exchange ratio to the Five9 board, and that Five9 would need to perform reverse due diligence on Zoom before agreeing to any proposal in order to understand the value of Zoom stock.

On April 6, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present at the invitation of the Five9 board. The Five9 board reviewed and discussed Zoom’s initial offer and Qatalyst Partners discussed with the Five9 board the financial aspects of the proposed terms. Mr. Trollope provided an update of his conversations with Mr. Yuan and indicated to the Five9 board that Mr. Trollope and Mr. Yuan intended to speak again later that day. The Five9 Board instructed Five9 management to continue seeking greater value from Zoom and to update the Five9 M&A Committee on the outcome of Mr. Trollope’s forthcoming conversation with Mr. Yuan.

Later on April 6, 2021, Mr. Yuan and Mr. Trollope discussed the proposed transaction, and Mr. Yuan informed Mr. Trollope that Zoom was increasing its proposal from an exchange ratio of 0.570 to an exchange ratio equal to an 18% premium to the closing trading price of Five9 common stock on April 5, 2021 (the last full day of trading prior to receipt of the offer), which equated to an exchange ratio of 0.592 per Five9 common share based on the closing trading price of Zoom Class A common stock on April 5, 2021.

After further discussion between Mr. Yuan and Mr. Trollope, Mr. Yuan, consistent with guidance Mr. Yuan had previously received from the Zoom board, increased the proposed exchange ratio to 0.600 shares of Zoom Class A common stock for each share of Five9 common stock (which we refer to as “Zoom’s April 6^th offer”), which represented a price per share of $197.87 based on the closing trading price of Zoom Class A common stock as of April 6, 2021 and a premium of approximately 18% to the closing trading price of Five9 common stock as of April 6, 2021.

Later on the same day, the Five9 M&A Committee held a special meeting to discuss Zoom’s April 6^th offer with Five9 management and representatives from Latham & Watkins and Qatalyst Partners present. Qatalyst Partners discussed financial aspects of the proposed terms of Zoom’s April 6^th offer with the Five9 M&A Committee. The Five9 M&A Committee authorized Five9 senior management to continue discussions with Zoom on the basis of Zoom’s April 6^th offer but noted that reverse diligence on Zoom would be critical to evaluating Zoom’s proposal more definitively at a subsequent meeting of the Five9 board. The Five9 M&A Committee also discussed the merits and risks of potential outreach to other potential strategic counterparties, including potential for strategic fit, such parties’ other strategic priorities, the regulatory profile of a potential transaction with such parties, such parties’ likely interest in, ability to consummate, and timeline with respect to a business combination with Five9, as well as the risk of leak posed by outreach to multiple parties. In light of the foregoing and the likelihood that the opportunity to engage in a transaction with Zoom could be lost if Five9 pursued other options, the Five9 M&A Committee determined not to contact third parties at that time.

Also on April 6, 2021, Mr. Trollope relayed the feedback from the Five9 M&A Committee to Mr. Yuan that Five9 was supportive of continuing to discuss a potential business combination transaction with Zoom. Later that same day, Mr. Zwarenstein provided Ms. Steckelberg with a list of reverse diligence requests.

On April 7, 2021, representatives of Qatalyst Partners and Goldman Sachs discussed Zoom’s April 6^th offer, reverse diligence matters and proposed timeline for entering into a strategic transaction. Throughout the following week, the parties continued to exchange diligence requests and responses.

On April 9, 2021, members of Zoom management gave a business, financial and operational update to members of Five9 management on a reverse diligence call, at which representatives of Qatalyst Partners and Goldman Sachs were present.

-52-

On April 12, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present at the invitation of the Five9 board. Representatives of Qatalyst Partners presented to the Five9 board on the status of reverse diligence and preliminary financial analysis and potential next steps. The Five9 board agreed on a negotiation strategy, including a counterproposal of an exchange ratio to be fixed as of the signing of a definitive merger agreement with such exchange ratio to represent a premium of 20% to the closing stock price of Five9 shortly before signing a definitive agreement with a floor of 0.600 shares of Zoom Class A common stock for each share of Five9 common stock (which we refer to as “Five9’s April 12^th proposal”). The Five9 board also discussed with Five9 management, as well as representatives of Qatalyst Partners and Latham & Watkins, the merits and risks of outreach to other potential strategic counterparties, including potential for strategic fit, such parties’ other strategic priorities, the regulatory profile of a potential transaction with such parties, such parties’ likely interest in, ability to consummate, and timeline with respect to a business combination with Five9, as well as the risk of a leak posed by outreach to multiple parties. In light of the foregoing and the likelihood that the opportunity to engage in a transaction with Zoom could be lost if Five9 pursued other options, the Five9 board confirmed the Five9 M&A Committee’s determination not to contact third parties at that time.

Also on April 12, 2021, at the instruction of the Five9 board, Mr. Trollope had a telephone conversation with Mr. Yuan and relayed Five9’s April 12^th proposal.

Also on April 12, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present to discuss the Five9 April 12^th proposal.

Later that same day, based on guidance from the Zoom transaction committee, Mr. Yuan delivered to Mr. Trollope a revised proposal to acquire Five9 in an all-stock transaction with a fixed exchange ratio representing a premium of 20% to the five-day volume-weighted average price (which we refer to as “VWAP”) of Five9 common stock, ending on the second trading day prior to the earlier of a leak and signing a merger agreement, subject to a cap of 0.6200 shares of Zoom Class A common stock for each share of Five9 common stock (which we refer to as “Zoom’s April 12^th offer”).

On April 13, 2021, after discussion with various members of the Five9 board and representatives of Qatalyst Partners, Mr. Trollope communicated a counterproposal to Mr. Yuan of a fixed exchange ratio representing a premium of 20% to the average of the daily closing exchange ratios (dividing the closing price of Five9 common stock by the closing price of Zoom Class A common stock for each day) for the five-day trading period prior to and including the second trading day prior to the signing of a definitive agreement, subject to a floor of 0.6000 and cap of 0.7000 shares of Zoom Class A common stock for each share of Five9 common stock.

On April 14, 2021, consistent with guidance from the Zoom transaction committee, Mr. Yuan communicated to Mr. Trollope that Five9’s counterproposal represented a valuation gap that was too large to bridge and that business combination discussions between the companies should be paused.

On April 15, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present at the invitation of the Five9 board. Representatives of Qatalyst Partners presented a summary of the financial aspects of the proposal based on the latest discussions with Zoom. The Five9 board determined to pause discussions and diligence efforts with Zoom.

On May 8, 2021, Mr. Yuan asked Mr. Trollope about the Five9 board’s current position regarding a potential business combination transaction between Five9 and Zoom, and Mr. Trollope indicated he believed the Five9 board would still be in favor of such a transaction with Zoom, if appropriate terms could be agreed.

On June 2, 2021, Mr. Trollope, Mr. Yuan and Mr. Zwarenstein attended the same social event but did not discuss the transaction. A member of the Zoom board attended the same event, and in conversation with

-53-

Mr. Trollope indicated that a potential transaction between Five9 and Zoom was still possible but would require closing the valuation gap.

On June 5, 2021, Mr. Trollope and Mr. Yuan met and discussed the ongoing commercial relationship between Zoom and Five9 and the potential for a business combination. Mr. Trollope noted to Mr. Yuan that if Zoom was serious about a potential transaction, Zoom should provide a letter of intent. Mr. Trollope also suggested that Zoom consider offering cash as part of or all of the consideration in any such proposal.

On June 7, 2021, the Chief Financial Officer of another publicly traded technology company (which we refer to as “Company A”) reached out to Mr. Zwarenstein and raised the possibility of a potential strategic transaction. Mr. Zwarenstein noted that any proposal for a strategic transaction involving Five9 would be reviewed by the Five9 board.

On June 12, 2021, the Chief Executive Officer of Company A sent a text message to Mr. Trollope to discuss the possibility of exploring a potential strategic transaction.

On June 13, 2021, Mr. Trollope met with the Chief Executive Officer of Company A, who conveyed Company A’s interest in an “at market” stock transaction with Five9, with no premium to Five9 stockholders. Mr. Trollope indicated that he did not expect the Five9 board to support a transaction without a premium to Five9 stockholders, but that any proposal for a strategic transaction involving Five9 would be reviewed by the Five9 board.

On June 14, 2021, Mr. Trollope informed Mr. Yuan that at least one other strategic party had expressed interest in a strategic transaction with Five9.

On June 15, 2021, Mr. Yuan made an oral offer to Mr. Trollope for Zoom to acquire Five9 in an all-stock transaction at a price of $190.00 per share of Five9 common stock, representing a premium of approximately 13% to the closing trading price of Five9 common stock as of June 14, 2021. Mr. Trollope indicated that the offer was unlikely to be viewed favorably by the Five9 board.

On June 16, 2021, the Five9 M&A Committee convened for a special meeting by videoconference with representatives of Five9 senior management and Qatalyst Partners present. Mr. Trollope updated the Five9 M&A Committee on the status of discussions with Zoom and Company A, including providing an update on the oral indications of interest provided by each party.

On June 17, 2021, Mr. Trollope and Mr. Yuan spoke by telephone. Mr. Yuan shared with Mr. Trollope a proposal from Zoom to acquire Five9 in an all-stock transaction at a price of $195.00 per share of Five9 common stock and then, as a result of discussion with Mr. Trollope, increased Zoom’s proposal to $200.00 per share of Five9 common stock, with the exchange ratio to be fixed at signing, or earlier in the event the proposal became public (which we refer to as “Zoom’s June 17^th offer”). The proposal represented a premium of approximately 20% to the closing trading price of Five9 common stock as of June 16, 2021 (the last full day of trading prior to receipt of the offer). Later that same day, Zoom sent Five9 a non-binding letter of intent reflecting Zoom’s June 17^th offer.

On June 18, 2021, the Five9 M&A Committee convened for a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present. Mr. Trollope updated the Five9 M&A Committee regarding Zoom’s June 17^th offer. Following discussion with Five9 management and its advisors, the Five9 M&A Committee instructed Mr. Trollope to provide Zoom with a counterproposal for an all-stock transaction at an implied price of $225.00 per share of Five9 common stock, with the exchange ratio to be fixed at signing based on the five-day VWAP of Zoom Class A common stock (which we refer to as “Five9’s June 18^th proposal”).

-54-

On June 19, 2021, Mr. Trollope met with the Chief Executive Officer of Company A to discuss a potential business combination. During the course of the meeting, Mr. Trollope noted the potential interest in Five9 from at least one other strategic party and Company A reiterated its interest in an all-stock “at market” transaction, with no premium to Five9 stockholders. The Chief Executive Officer of Company A also noted that it would take several months before Company A would be in position to enter into such a transaction.

Later on June 19, 2021, Mr. Trollope and Mr. Yuan met for dinner. Mr. Trollope conveyed to Mr. Yuan Five9’s June 18^th proposal. Mr. Yuan then increased Zoom’s June 17^th offer to acquire Five9 in an all-stock transaction for $210 per share of Five9 common stock, with a fixed exchange ratio to be calculated based on the five-day VWAP of Zoom Class A common stock ending on the second trading day prior to the earlier of a leak and signing a definitive merger agreement, subject to approval from the Zoom board (which we refer to as “Zoom’s June 19^th offer”). Zoom’s June 19^th offer represented a premium of approximately 15 % to the closing trading price of Five9 common stock as of June 18, 2021 (the last full day of trading prior to receipt of the offer).

On June 20, 2021, in a text message exchange with Mr. Trollope, Mr. Yuan indicated that Zoom’s June 19^th offer included an exclusivity period for due diligence and negotiation of definitive documentation. Mr. Trollope indicated he would discuss Zoom’s proposal with the Five9 board.

On June 21, 2021, Zoom sent Five9 an updated non-binding letter of intent reflecting Zoom’s June 19^th offer previously outlined by Mr. Yuan, including a thirty-day exclusivity period.

On June 22, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 management and representatives of Latham & Watkins and Qatalyst Partners. Mr. Trollope updated the Five9 board on Zoom’s June 19^th offer and request for exclusivity. Representatives of Qatalyst Partners discussed financial aspects of the proposed terms of the transaction and preliminary valuation framework based on Zoom’s June 19^th offer. After discussion with Five9 management and Five9’s advisors, the Five9 board determined to proceed with Zoom’s June 19^th offer, assuming Zoom was willing to remove its request for exclusivity. The Five9 board also discussed the merits of potential outreach to other potential strategic counterparties, including Company A, including the potential risks associated with any outreach. The Five9 board then instructed Mr. Trollope to contact Company A to determine the nature and likelihood of the potential transaction previously raised by Company A’s Chief Executive Officer, but determined to not pursue outreach to additional third parties due to concerns about confidentiality and risks it could pose to the ongoing discussions with Zoom.

Later that same day, Mr. Trollope communicated to Mr. Yuan the Five9 board’s view that exclusivity should be removed from the proposal.

Later on June 22, 2021, Zoom sent Five9 an updated non-binding letter of intent reflecting Zoom’s June 19^th offer, but removing the request for exclusivity (which we refer to as “Zoom’s June 22^nd offer”).

Also on June 22, 2021, as directed by the Five9 board, Mr. Trollope contacted the Chief Executive Officer of Company A to discuss the seriousness of Company A’s interest in a potential transaction, to which Company A reiterated its interest in a strategic transaction with Five9, but declined to enter into a confidentiality agreement to facilitate the confidential exchange of information.

On June 24, 2021, Mr. Trollope informed Mr. Yuan that the Five9 board had approved moving forward on the terms set forth in the non-binding letter of intent reflecting Zoom’s June 22^nd offer, including agreement as to the methodology for calculating the exchange ratio set forth therein. Messrs. Yuan and Trollope agreed that the parties should move forward but that the letter of intent did not need to be signed.

On June 27, 2021, representatives of Cooley furnished an initial draft of a merger agreement to Latham & Watkins. The initial draft merger agreement contemplated a “no-shop” provision restricting Five9 from soliciting alternative acquisition proposals and provided for a termination fee of 3.75% of the equity value of Five9 implied by the exchange ratio, payable from Five9 to Zoom in certain scenarios, including if the merger agreement with Zoom were to be terminated in favor of an unsolicited superior proposal.

-55-

From June 27, 2021 to July 16, 2021, representatives of Five9 and Zoom, with the assistance of Latham & Watkins and Cooley and other professional advisors, negotiated the terms of the merger agreement and related documents.

On June 28, 2021, Five9 granted Zoom and its advisors access to due diligence information provided in a virtual data room. From June 28, 2021 until the execution and delivery of the merger agreement on July 16, 2021, Zoom and its representatives conducted due diligence on Five9 and participated in multiple due diligence discussions with Five9’s management and Five9’s representatives. Five9 and its representatives continued their reverse due diligence on Zoom with respect to, among other things, Zoom’s financials, legal matters, operations and performance that Five9 and its representatives had initially commenced in March 2021 and participated in due diligence discussions with Zoom’s management and representatives.

On July 1, 2021, the Five9 M&A Committee convened for a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present. Latham & Watkins provided an overview of the key terms of the initial merger agreement and proposed responses, including a revised termination fee of 2.75% of Five9’s equity value. The Five9 M&A Committee discussed the terms of the merger agreement and directed Latham & Watkins to provide a revised merger agreement to Cooley reflecting the Five9 M&A Committee’s discussions.

Later on July 1, 2021, representatives of Latham & Watkins provided a markup of the draft merger agreement to Cooley, which proposed, among other terms, a termination fee of 2.75% of Five9’s equity value.

On July 6, 2021, Mr. Trollope spoke with the Chief Executive Officer of Company A, during which Company A’s Chief Executive Officer reiterated that a Five9 transaction with Company A would be an “at market” stock transaction with no premium to Five9 stockholders.

Later on July 6, 2021, the Five9 board held a call by videoconference to provide a transaction update and consider employee retention matters in connection with a potential transaction with representatives of Five9 senior management and representatives of Latham & Watkins present. Mr. Trollope updated the Five9 board on his discussions with the Chief Executive Officer of Company A. Following discussion among the Five9 board members and Five9 management regarding Company A’s proposal and its level of interest in a transaction with Five9, the Five9 board determined that Company’s A’s proposed terms were not sufficiently compelling to warrant further engagement at that time.

During the course of the week of July 6, 2021, Mr. Trollope updated the other members of the Five9 board not present at the July 6, 2021 meeting on his discussions with Company A and such members of the Five9 board agreed with the decision to not engage further with Company A at that time.

Also on July 6, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Members of Zoom management gave an update on the status of the diligence performed to date. Representatives of Goldman Sachs gave an overview of the status of the potential transaction with Five9, including an update from representatives of Goldman Sachs regarding trading and preliminary financial analysis.

On July 9, 2021, representatives of Cooley sent Latham & Watkins a revised draft merger agreement which proposed, among other terms, a termination fee of 3.5% of Five9’s equity value.

Also on July 9, 2021, Mr. Trollope and Mr. Yuan had a phone call during which, among other topics, Mr. Yuan conveyed the Zoom board’s desire for Mr. Trollope to continue with the combined company following the closing of a potential transaction and Mr. Trollope’s potential role in that scenario. Mr. Trollope had no prior discussions with Mr. Yuan regarding Mr. Trollope’s role with the combined company and indicated that discussions regarding his role could move forward only after material terms regarding the business combination were agreed and execution of a merger agreement was imminent.

-56-

Also on July 9, 2021, the Five9 M&A Committee approved the Updated Five-Year Plan (as more fully described in the section entitled “—Projected Financial Information”) and approved Five9 management providing the Updated Five-Year Plan to Zoom.

Also on July 9, 2021, the Zoom board held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Members of Zoom management gave an overview of the strategic rationale and structure for a potential strategic transaction with Five9, an update on the status and findings of the diligence performed to date and presented Five9’s Updated Five-Year Plan to the Zoom board. Representatives of Goldman Sachs gave an update regarding trading and preliminary financial analysis.

On July 11, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present. Representatives of Latham & Watkins reviewed the directors’ fiduciary duties in connection with the Five9 board’s consideration of the proposed transaction and provided an overview of the key merger agreement terms and proposed responses. Discussion ensued and the Five9 board then directed Latham & Watkins to provide a markup of the merger agreement to Cooley reflecting the Five9 board’s discussion, including a termination fee of 2.9% of Five9’s equity value. The Five9 board then reviewed the Updated Five-Year Plan and related extrapolated projections for fiscal years 2027 through 2031 and directed Qatalyst Partners to use such projections and extrapolations for purposes of the financial analysis for its fairness opinion. Qatalyst then presented the Five9 board with a summary of the financial aspects of the proposed terms of the transaction and proposed exchange ratio and a discussion ensued regarding the financial aspects of the proposal. The Five9 board also discussed regulatory issues that may impact the deal. Members of the Five9 management team provided the Five9 board with an update on Five9’s reverse diligence on Zoom. Mr. Trollope provided the Five9 board with an update on his discussions with Mr. Yuan regarding Mr. Trollope’s potential role with the combined company following the closing of the proposed transaction, which the Five9 board discussed in executive session.

Later that same day, representatives of Latham & Watkins provided a markup of the draft merger agreement to Cooley, which proposed, among other terms, a termination fee of 2.9% of Five9’s equity value.

On July 13, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present. Mr. Trollope provided the Five9 board with an update on discussions with Zoom, including with respect to his proposed role with the combined company, which was contemplated to be a president of Zoom and Chief Executive Officer of Five9. Representatives of Latham & Watkins then provided an update on the anticipated regulatory filings required in connection with the transaction, anticipated timing for approvals and the status of negotiations between the parties. A discussion ensued regarding open issues, including settlement on a final exchange ratio, and the proposed signing and announcement timeline.

Also on July 13, 2021, Cooley sent Latham & Watkins a revised draft merger agreement which proposed, among other terms, a termination fee of 3.25% of Five9’s equity value.

Over the course of July 13, 2021 to July 16, 2021, representatives of Latham & Watkins and Cooley exchanged several revised versions of the draft merger agreement reflecting the parties’ discussions, including the negotiation of the termination fee and antitrust and regulatory provisions, with the final terms of the merger agreement (pending approval by each of the Five9 board and the Zoom board) reflecting a termination fee of $450 million (approximately 3.1% of Five9’s equity value) and a fiduciary termination right in favor of Five9.

On July 13, 2021, Zoom sent a draft offer letter to Mr. Trollope, and in the period between receipt of the offer letter and signing of the merger agreement, and with the permission of the Five9 board, Mr. Trollope engaged in further discussions with Mr. Yuan regarding his role with the combined company following the closing of the merger and the terms of his employment.

-57-

On July 14, 2021, the Zoom transaction committee held a meeting with members of Zoom management and representatives of Goldman Sachs and Cooley present. Members of Zoom management gave an update on the status and findings of the diligence performed to date and an update on the communications strategy related to the announcement of the potential transaction should the potential transaction be approved. Representatives of Cooley gave an overview of the material terms of the proposed merger agreement, including which terms remained subject to ongoing negotiation. Representatives of Goldman Sachs gave an overview of the status of the potential transaction with Five9, including an update from representatives of Goldman Sachs regarding trading and preliminary financial analysis.

On July 16, 2021, Mr. Trollope, Mr. Zwarenstein, Mr. Yuan, and Ms. Steckelberg held a telephonic conference during which they finalized the exchange ratio at 0.5533 shares of Zoom Class A common stock for each share of Five9 common stock, based on the previously agreed calculation methodology. Based on the closing price of the Zoom Class A common stock on July 16, 2021, the exchange ratio of 0.5533 shares of Zoom Class A common stock for each share of Five9 common stock represented an implied value of $200.28 per share of Five9 common stock and represented a premium of approximately 13% to the Five9 closing trading price on July 16, 2021.

After market close on July 16, 2021, the Zoom board held a meeting to consider and discuss the terms of the proposed transaction with Five9 by Zoom with members of Zoom management, representatives of Goldman Sachs and representatives of Cooley present. Representatives of Goldman Sachs discussed with the Zoom board certain financial aspects of the proposed transaction. Zoom’s management reviewed the proposed per share consideration to be paid to Five9 stockholders at an exchange ratio of 0.5533 shares of Zoom Class A common stock for each share of Five9 common stock. Representatives of Cooley reviewed with the Zoom board the Zoom board’s fiduciary duties in connection with the proposed transaction. Representatives of Cooley summarized the material terms and conditions of the proposed transaction. The Zoom board then engaged in discussion and deliberations, following which and taking into account the factors described in greater detail in the section entitled “—Reasons for the Merger— Zoom’s Reasons for the Merger,” the Zoom board approved the merger agreement and determined that the merger agreement and the transactions contemplated thereby, including the merger and the issuance of Zoom Class A common stock in connection therewith, were advisable and fair to, and in the best interests of, Zoom and its stockholders.

Later on July 16, 2021, the Five9 board held a special meeting by videoconference with representatives of Five9 senior management and representatives of Latham & Watkins and Qatalyst Partners present. Representatives of Latham reviewed with the Five9 board its fiduciary duties in connection with a decision to engage in the proposed transaction and provided a summary of the material terms and conditions of the proposed transaction. Representatives of Qatalyst Partners reviewed and discussed its financial analysis regarding the proposed merger consideration contemplated by the exchange ratio of 0.5533 shares of Zoom Class A common stock for each share of Five9 common stock based on the management projections. Thereafter, at the request of the Five9 board, representatives of Qatalyst Partners rendered to the Five9 board Qatalyst Partners’ oral opinion, which was subsequently confirmed by delivery of a written opinion, dated July 16, 2021, to the effect that, as of July 16, 2021, based upon and subject to the procedures followed and assumptions, qualifications and limitations considered in connection with the preparation of the opinion, the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom) was fair, from a financial point of view, to such holders, as further described in the section entitled “—Opinion of Five9’s Financial Advisor.” Mr. Trollope also provided the Five9 board with an update of his post-closing employment discussions with Zoom, which the Five9 board discussed and considered in executive session.

After discussion and taking into account the factors described in greater detail in the section entitled “Reasons for the Merger— Recommendation of the Five9 Board and Reasons for the Merger,” the Five9 board unanimously (i) determined the terms of the merger agreement and transactions contemplated thereby, including the merger, to be fair to and in the best interests of Five9 and its stockholders, (ii) determined that it is in the best

-58-

interests of Five9 and its stockholders, and declared it advisable, to enter into the merger agreement, (iii) approved the execution and delivery by Five9 of the merger agreement, the performance by Five9 of its covenants and agreements contained therein and the consummation of the merger and the other transactions contemplated by the merger agreement upon the terms and subject to the conditions contained therein and (iv) directed that the merger agreement be submitted for consideration at a meeting of Five9’s stockholders and recommended that the holders of Five9’s common stock approve the transactions contemplated by the merger agreement, and adopt the merger agreement, subject to Section 5.3 of the merger agreement.

Later on July 16, 2021, Five9, Zoom and Merger Sub executed the merger agreement. Mr. Trollope also then executed an offer letter with Zoom governing the terms of his employment following the closing of the merger, as described further in the section entitled “—Interests of Five9 Directors and Officers in the Merger.”

On July 18, 2021, Five9 and Zoom issued a joint press release announcing the transaction.

Reasons for the Merger

Zoom’s Reasons for the Merger

In reaching its decision to approve the merger agreement and the transactions contemplated by the merger agreement, the Zoom board carefully considered the merger and the transactions contemplated by the merger agreement, consulted with Zoom’s management, as well as Zoom’s legal and financial advisors, and considered a number of factors, including the following factors which it viewed as supporting its decision to approve the merger agreement and the transactions contemplated by the merger agreement (not in any relative order of importance):

-59-

The Zoom board also considered a variety of uncertainties and risks and other potentially negative factors concerning the transactions, including the following (not in any relative order of importance):

-60-

The Zoom board concluded that the potential negative factors associated with the merger were outweighed by the potential benefits of the merger. Accordingly, the Zoom board approved the merger agreement and the transactions contemplated by the merger agreement.

The foregoing discussion of the information and factors considered by the Zoom board is not intended to be exhaustive, but includes the material positive and negative factors considered by the Zoom board. Given the variety of factors considered in connection with its evaluation of the acquisition, the Zoom board did not find it practicable to, and did not, quantify or otherwise assign relative weights to the specific factors considered in

-61-

reaching its determination. In addition, individual directors may have given different weights to different factors. The Zoom board did not undertake to make any specific determination as to whether any factor, or any particular aspect of any factor, supported or did not support its ultimate determination. The Zoom board based its determination on the totality of the information presented.

Recommendation of the Five9 Board and Reasons for the Merger

By unanimous vote, the Five9 board, at a special meeting held on July 16, 2021, determined that the merger agreement and the transactions contemplated by the merger agreement, including the merger, are fair to, and in the best interests of Five9 and its stockholders; approved and declared advisable the merger agreement and the transactions contemplated thereby, including the merger; and resolved to recommend that Five9 stockholders approve the transactions contemplated by the merger agreement, including the merger, and adopt the merger agreement. The Five9 board unanimously recommends that you vote “FOR” the merger proposal, “FOR” the non-binding compensation advisory proposal and “FOR” the adjournment proposal.

In evaluating the merger, the Five9 board consulted with Five9’s senior management team, as well as Five9’s outside legal and financial advisors, and, in reaching its decision to approve the merger agreement and declare its advisability and to recommend that Five9’s stockholders vote in favor of the adoption of the merger agreement, the Five9 board considered a number of factors, including, but not limited to, the following (which are not necessarily presented in order of their relative importance to the Five9 board):

-62-

-63-

Five9’s board also considered a number of potentially negative factors in its deliberations concerning the merger agreement and the merger, including:

-64-

In the judgment of Five9’s board, however, these potential risks were more than offset by the potential benefits of the merger discussed above.

The foregoing discussion of the information and factors considered by the Five9 board is not intended to be exhaustive, but includes the material factors that the Five9 board considered. In reaching its decision to approve the merger agreement and the transactions contemplated by the merger agreement, including the merger, the Five9 board did not quantify or assign any relative weights to the factors considered, and individual directors may have given different weights to different factors. The Five9 board considered all these factors as a whole, and overall considered the factors to be favorable to, and to support, its determination. The Five9 board conducted an overall review of the factors described above, and unanimously determined that the merger is fair to, advisable to, and in the best interests of, Five9 and Five9’s stockholders.

In considering the recommendation of Five9’s board to adopt the merger agreement, Five9’s stockholders should be aware that the executive officers and directors of Five9 have certain interests in the merger that may be different from, or in addition to, the interests of Five9 stockholders generally, as more fully described in the section entitled “—Interests of Five9 Directors and Executive Officers in the Merger.” The Five9 board was aware of these interests and considered them when approving the merger agreement and recommending that Five9 stockholders vote to adopt the merger agreement.

Projected Financial Information

Although Five9 has publicly issued limited short-term guidance concerning certain aspects of its expected financial performance, it does not, as a matter of course, make public disclosure of detailed forecasts or

-65-

projections of its expected financial performance for extended periods due to, among other things, the inherent difficulty of accurately predicting future periods and the likelihood that the underlying assumptions and estimates may prove incorrect. However, in connection with the transaction with Zoom, Five9’s senior management prepared and approved for use certain unaudited prospective financial information which was provided to and considered by the Five9 board and Zoom, and which was provided to Qatalyst Partners, in each case as set forth herein.

Five9’s management initially prepared certain non-public, unaudited prospective financial information for the remainder of the 2021 fiscal year and for fiscal years 2022 through 2026 in March 2021 (which we refer to as the “Initial Five-Year Plan”) and such non-public, unaudited prospective financial information was discussed with, and recommended to the Five9 board of directors by, the Five9 M&A Committee on March 24, 2021 and subsequently discussed with, and approved for use by, the Five9 board on March 25, 2021 in connection with the evaluation of the strategic transaction with Zoom. The Initial Five-Year Plan was shared with representatives of Zoom on March 26, 2021 in connection with Zoom’s due diligence review.

In July 2021, the Initial Five-Year Plan was adjusted to reflect the Company’s actual operating results for the first quarter of 2021 and Five9’s revised estimates for its results for second quarter of 2021, together with updated expectations for capital expenditures as well as the expected tax benefits resulting from recent updates to Five9’s tax planning (which we refer to as the “Updated Five-Year Plan”). The Five9 M&A Committee approved the Updated Five-Year Plan on July 9, 2021 and the provision thereof to Qatalyst Partners and Zoom. The Updated Five-Year Plan was shared with representatives of Zoom on July 9, 2021 in connection with Zoom’s due diligence review.

Five9’s senior management subsequently made certain unaudited prospective extrapolations based on the Updated Five-Year Plan for fiscal years 2027 through 2031. The Five9 board approved the Updated Five-Year Plan and such extrapolations on July 11, 2021. Such extrapolations were not provided to representatives of Zoom in connection with the transaction. In connection with such approval, the Five9 board directed Qatalyst Partners to use the Updated Five-Year Plan and the related extrapolations for fiscal years 2027 through 2031 in performing its financial analysis in connection with its opinion, as described in more detail in the section entitled “—Opinion of Five9’s Financial Advisor.”

We refer to any of the Initial Five-Year Plan, the Updated Five-Year Plan and related extrapolated projections for fiscal years 2027 through 2031 as the “management projections.” The Management Projections were prepared by Five9 on a stand-alone basis and do not take into account the transactions, including any costs incurred in connection with the merger or the other transactions contemplated by the merger agreement or any changes to Five9’s operations or strategy that may be implemented after the completion of the merger. As a result, actual results likely will differ, and may differ materially, from those contained in the management projections.

The information and tables set forth below are included solely to give Five9 stockholders access to relevant portions of the management projections and are not included in this proxy statement/prospectus to influence any Five9 stockholder to vote their shares of Five9 common stock in favor of the merger or for any other purpose.

Initial Five-Year Plan

-66-

Updated Five-Year Plan and Related Extrapolations

Important Information About the Management Projections

The management projections were not prepared with a view toward public disclosure or toward complying with U.S. generally accepted accounting principles (which we refer to as “GAAP”), nor were they prepared with a view toward compliance with the published guidelines of the SEC, or the guidelines established by the American Institute of Certified Public Accountants for preparation and presentation of projections of prospective financial information. The non-GAAP financial measures used in the management projections were approved by Five9 for the use by its financial advisor in connection with its opinion and were relied upon by the Five9 board in connection with its consideration of the merger agreement and the transactions contemplated by the merger agreement, including the merger. The SEC rules, which would otherwise require a reconciliation of a non-GAAP financial measure to a GAAP financial measure, do not apply to non-GAAP financial measures provided to Qatalyst Partners or to the Five9 board in connection with a proposed business combination like the merger if the disclosure is included in a document like this proxy statement/prospectus. In addition, reconciliations of non-GAAP financial measures to a GAAP financial measure were not relied upon by Qatalyst Partners for purposes of its opinion or by the Five9 board in connection with its consideration of the merger agreement and the transactions contemplated by the merger agreement, including the merger. Accordingly, Five9 has not provided a reconciliation of the financial measures included in the management projections to the relevant GAAP financial measures. In addition, the management projections were not prepared with a view towards complying with GAAP. The management projections may differ from published analyst estimates and forecasts and do not take into account any events or circumstances after the date they were prepared, including the announcement of the merger.

-67-

While the management projections are presented with numerical specificity, the management projections were based on numerous variables and assumptions that are inherently uncertain and may be beyond Five9 management’s control. Further, given that the management projections cover multiple years, by their nature, they become subject to greater uncertainty with each successive year beyond their preparation. Important factors that may affect actual results and may result in such projections not being achieved include: the occurrence of any event, change or other circumstances that could give rise to the termination of the merger agreement, the inability to complete the merger, or the failure to satisfy other conditions to completion of the merger, including that a governmental entity may prohibit, delay or refuse to grant approval for the completion of the merger, and risks and uncertainties pertaining to Five9’s business, including the risks and uncertainties detailed in Five9’s public periodic filings with the SEC. In addition, the ability to achieve the management projections may depend on, in part, whether or not the strategic goals, objectives and targets are reached over the applicable period. The assumptions upon which the management projections were based necessarily involve judgments with respect to, among other things, future economic, competitive and regulatory conditions and financial market conditions and future business decisions that may not be realized and that are inherently subject to significant business, economic, competitive and regulatory uncertainties and contingencies, including, among other things, the inherent uncertainty of the business and economic conditions affecting the industry in which Five9 operates, and the risks and uncertainties described in the section entitled “Cautionary Statement Regarding Forward-Looking Statements,” all of which are difficult or impossible to predict accurately and many of which are beyond Five9’s control. The Management Projections also reflect assumptions by Five9 management that are subject to change and are susceptible to multiple interpretations and periodic revisions based on actual results, revised prospects for the Five9 business, changes in general business or economic conditions, or any other transaction or event that has occurred or that may occur and that was not anticipated when such projections were prepared.

Accordingly, there can be no assurance that the management projections will be realized, and actual results may differ, and may differ materially, from those shown. The inclusion of the management projections in this proxy statement/prospectus should not be regarded as an indication that any of Five9, Qatalyst Partners, Zoom or any of their respective affiliates, officers, directors, advisors or other representatives considered or consider the management projections necessarily predictive of actual future events, and the management projections should not be relied upon as such. None of Five9, Qatalyst Partners, Zoom or any of their respective affiliates, officers, directors, advisors or other representatives can give any assurance that actual results will not differ from the management projections. None of Five9, Qatalyst Partners, Zoom or any of their respective affiliates, officers, directors, advisors or other representatives has made or makes any representation to any stockholder or other person regarding the ultimate performance of Five9 compared to the information contained in the management projections or that forecasted results will be achieved.

In addition, the management projections have not been updated or revised to reflect information or results after the date they were prepared or as of the date of this proxy statement/prospectus, and except as required by applicable securities laws, Five9 does not intend to update or otherwise revise the management projections or the specific portions presented to reflect circumstances existing after the date when made or to reflect the occurrence of future events, even in the event that any or all of the underlying assumptions are shown to be in error.

The management projections were prepared by, and are the responsibility of, Five9’s management. KPMG LLP has not audited, reviewed, examined, compiled nor applied agreed-upon procedures with respect to the management projections and, accordingly, KPMG LLP does not express an opinion or any other form of assurance with respect thereto. The KPMG LLP report incorporated by reference for Five9 relates to Five9’s previously issued financial statements. It does not extend to the management projections and should not be read to do so.

Opinion of Five9’s Financial Advisor

Five9 retained Qatalyst Partners to act as its financial advisor in connection with a potential strategic transaction and to evaluate whether the exchange ratio to be received pursuant to, and in accordance with, the

-68-

terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom) was fair, from a financial point of view, to such holders. Five9 selected Qatalyst Partners to act as its financial advisor based on Qatalyst Partners’ qualifications, expertise, reputation and knowledge of the business and affairs of Five9 and the industry in which it operates. Qatalyst Partners has provided its written consent to the reproduction of its opinion in this proxy statement/prospectus. At the meeting of the Five9 board on July 16, 2021, Qatalyst Partners rendered to the Five9 board its oral opinion, subsequently confirmed in writing, to the effect that, as of the date thereof and based upon and subject to the various assumptions, qualifications, limitations and other matters set forth therein, the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom) was fair, from a financial point of view, to such holders. Qatalyst Partners delivered its written opinion, dated July 16, 2021, to the Five9 board following the meeting of the Five9 board.

The full text of Qatalyst Partners’ written opinion, dated July 16, 2021, is attached hereto as Annex B and is incorporated by reference herein. The opinion sets forth, among other things, the assumptions made, procedures followed, matters considered and limitations and qualifications of the review undertaken by Qatalyst Partners in rendering its opinion. The holders of Five9 common stock should read the opinion carefully in its entirety. Qatalyst Partners’ opinion was provided to the Five9 board and addresses only, as of the date of the opinion, the fairness, from a financial point of view, of the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 Common Stock (other than Zoom or any affiliate of Zoom) and it does not address any other aspect of the merger. It does not constitute a recommendation as to how any holder of shares of Five9 common stock should vote with respect to the merger or any other matter and does not in any manner address the price at which Five9 common stock or Zoom Class A common stock will trade or otherwise be transferable at any time. The summary of Qatalyst Partners’ opinion set forth herein is qualified in its entirety by reference to the full text of the opinion, which is attached to this proxy statement/prospectus as Annex B.

In arriving at its opinion, Qatalyst Partners reviewed the merger agreement, certain related documents and certain publicly available financial statements and other business and financial information of Five9 and Zoom. Qatalyst Partners also reviewed certain forward-looking information relating to Five9 prepared by the management of Five9, including financial projections and operating data of Five9, which we refer to as the management projections, described below in the section entitled “—Projected Financial Information.” Additionally, Qatalyst Partners discussed the past and current operations and financial condition and the prospects of Five9 and Zoom with senior executives of Five9 and Zoom, respectively. Qatalyst Partners also reviewed the historical market prices and trading activity for Five9 common stock and Zoom Class A common stock and compared the financial performance of Five9 and Zoom and the prices and trading activity of the Five9 common stock and Zoom Class A common stock with that of certain other selected publicly traded companies and their securities. In addition, Qatalyst Partners reviewed the financial terms, to the extent publicly available, of selected acquisition transactions and performed such other analyses, reviewed such other information and considered such other factors as Qatalyst Partners deemed appropriate.

In arriving at its opinion, Qatalyst Partners assumed and relied upon, without independent verification, the accuracy and completeness of the information that was publicly available or supplied or otherwise made available to, or discussed with, Qatalyst Partners by Five9 and Zoom. With respect to the management projections, Qatalyst Partners was advised by the management of Five9, and Qatalyst Partners assumed, that the management projections had been reasonably prepared on bases reflecting the best currently available estimates and judgments of the management of Five9 of the future financial performance of Five9 and other matters covered thereby. Qatalyst Partners assumed that the merger will be consummated in accordance with the terms set forth in the merger agreement, without any modification, waiver or delay and that the merger will have the tax consequences as set forth in the merger agreement and as described in discussions with representatives of Five9. In addition, Qatalyst Partners assumed, that in connection with the receipt of all the necessary approvals of the merger, no delays, limitations, conditions or restrictions will be imposed that could have an adverse effect on

-69-

Five9, Zoom or the contemplated benefits expected to be derived in the merger. Qatalyst Partners did not make any independent evaluation or appraisal of the assets or liabilities (contingent or otherwise) of Five9, Zoom or their respective affiliates, nor was Qatalyst Partners furnished with any such evaluation or appraisal. In addition, Qatalyst Partners relied, without independent verification, upon the assessment of the management of Five9 as to the existing and future technology and products of Five9 and the risks associated with such technology and products. In arriving at its opinion, Qatalyst Partners was not authorized to solicit, and did not solicit, interest from any party with respect to an acquisition, business combination or other extraordinary transaction involving Five9. Qatalyst Partners’ opinion has been approved by its opinion committee in accordance with its customary practice.

Qatalyst Partners’ opinion is necessarily based on financial, economic, market and other conditions as in effect on, and the information made available to it as of, the date of the opinion. Events occurring after the date of the opinion may affect Qatalyst Partners’ opinion and the assumptions used in preparing it, and Qatalyst Partners has not assumed any obligation to update, revise or reaffirm its opinion. Qatalyst Partners’ opinion does not address the underlying business decision of Five9 to engage in the merger, or the relative merits of the merger as compared to any strategic alternatives that may be available to Five9. Qatalyst Partners’ opinion is limited to the fairness, from a financial point of view, of the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom) and Qatalyst Partners expressed no opinion with respect to the fairness of the amount or nature of the compensation to any of the officers, directors or employees of Five9 or Zoom or any of their respective affiliates, or any class of such persons, relative to such exchange ratio.

The following is a brief summary of the material analyses performed by Qatalyst Partners in connection with its opinion dated July 16, 2021. The analyses and factors described below must be considered as a whole; considering any portion of such analyses or factors, without considering all analyses and factors, could create a misleading or incomplete view of the process underlying Qatalyst Partners’ opinion. For purposes of its analyses, Qatalyst Partners utilized both third-party research analyst consensus estimates as of July 16, 2021 (which we refer to as the “street case”), and the management projections, described below in the section entitled “—Projected Financial Information.” Some of the summaries of the financial analyses include information presented in tabular format. The tables are not intended to stand alone, and in order to more fully understand the financial analyses used by Qatalyst Partners, the tables must be read together with the full text of each summary. Considering the data set forth below without considering the full narrative description of the financial analyses, including the methodologies and assumptions underlying the analyses, could create a misleading or incomplete view of Qatalyst Partners’ financial analyses.

Illustrative Discounted Cash Flow Analysis

Qatalyst Partners performed an illustrative discounted cash flow analysis, which is designed to imply a range of potential per-share present values for Five9 common stock as of June 30, 2021 (which is the end of Five9’s most recent completed fiscal quarter and most recent balance sheet date) by:

-70-

Based on the calculations set forth above, this analysis implied a range of values for Five9 common stock of approximately $109.47 to $240.87 per share and a range of implied exchange ratios, based on the Zoom Class A common stock closing share price of $361.97 as of July 16, 2021, of 0.3024x to 0.6654x.

Illustrative Selected Companies Analysis

Qatalyst Partners reviewed and compared selected financial information and public market multiples for Five9 with publicly available financial information and public market multiples for selected companies. The companies used in this comparison were those companies listed below, which were selected by Qatalyst Partners in its professional judgment, based on factors including that they are publicly traded companies in similar lines of business to Five9, have a similar business model, have similar financial performance or have other relevant or similar characteristics.

Based upon third-party research analyst consensus estimates as of July 16, 2021 and using the closing prices as of July 16, 2021 for shares of the selected companies, Qatalyst Partners calculated, among other things, the fully-diluted enterprise value divided by the estimated consensus revenue for the calendar year 2022 (which we refer to as the “CY2022E revenue multiples”), for each of the selected companies, as shown below:

-71-

Based on an analysis of the CY2022E revenue multiples for the selected companies and the application of its professional judgment, Qatalyst Partners selected a representative multiple range of 14.0x to 22.0x. Qatalyst Partners noted that the CY2022E revenue multiple for Five9 was 20.0x based on the street case and Five9’s closing price as of July 16, 2021.

Qatalyst Partners then applied this range to Five9’s estimated revenue for calendar year 2022, based on the management projections and based on the street case. Qatalyst Partners then added the cash and cash equivalents of Five9 as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and subtracted (i) the face value of Five9’s outstanding convertible notes, as of July 14, 2021, as provided by Five9 management and (ii) the value of Five9’s finance leases as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and divided the resulting amount by the number of fully diluted shares of Five9 Common Stock outstanding as of July 14, 2021 (calculated utilizing the same methodology as used in the above discounted cash flow analysis). This analysis implied (a) a range of values for Five9 common stock of approximately $159.48 to $247.54 per share, and implied exchange ratios based on the Zoom Class A common stock closing share price of $361.97 as of July 16, 2021, of 0.4406x to 0.6839x, based on the management projections for calendar year 2022 and (b) a range of values for Five9 common stock of approximately $124.28 to $195.33 per share, and implied exchange ratios based on the Zoom Class A common stock closing share price of $361.97 as of July 16, 2021, of 0.3433x to 0.5396x, based on the street case for calendar year 2022.

No company included in the selected companies analysis is identical to Five9. In evaluating the selected companies, Qatalyst Partners made judgments and assumptions with regard to industry performance, general business, economic, market and financial conditions and other matters. Many of these matters are beyond the control of Five9, such as the impact of competition on Five9’s business or the industry in general, industry growth and the absence of any material adverse change in Five9’s financial condition and prospects or the industry or in the financial markets in general. Individual multiples or mathematical analysis, such as determining the arithmetic mean, median, or the high or low, is not in itself a meaningful method of using selected company data.

Illustrative Selected Transactions Analysis

Qatalyst Partners compared sixteen selected public company transactions, including transactions involving companies participating in similar lines of business to Five9 or with similar business models, similar financial performance or other relevant or similar characteristics.

For each of the selected transactions listed below, Qatalyst Partners reviewed, among other things, (a) the implied fully diluted enterprise value of the target company as a multiple of last-twelve-months revenue of the target company (which we refer to as the “LTM revenue multiples”) and (b) the implied fully diluted enterprise value of the target company as a multiple of third-party research analyst consensus estimates of the next-twelve-months revenue of the target company (which we refer to as the “NTM revenue multiples”).

-72-

Based on the analysis of the LTM revenue multiples for the selected transactions and its professional judgment, Qatalyst Partners selected a representative multiple range of 20.0x to 37.5x. Qatalyst Partners applied this range to Five9’s revenue (calculated for the twelve-month period ended on March 31, 2021) based on Five9’s financial statements filed with the SEC by Five9 on April 29, 2021. Qatalyst Partners then added the cash and cash equivalents of Five9 as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and subtracted (i) the face value of Five9’s outstanding convertible notes, as of July 14, 2021, as provided by Five9 management and (ii) the value of Five9’s finance leases as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and divided the resulting amount by the number of fully diluted shares of Five9 common stock outstanding as of July 14, 2021 (calculated utilizing the same methodology as used in the above discounted cash flow analysis). This analysis implied a range of values for Five9 common stock of approximately $130.58 to $242.18 per share, and implied exchange ratios based on the Zoom Class A common stock closing share price of $361.97 as of July 16, 2021, of 0.3607x to 0.6691x.

Based on the analysis of the NTM revenue multiples for the selected transactions and its professional judgment, Qatalyst Partners selected a representative multiple range of 15.0x to 29.0x. Qatalyst Partners applied this range to Five9’s revenue (calculated for the twelve-month period ending on March 31, 2022) based on the street case. Qatalyst Partners then added the cash and cash equivalents of Five9 as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and subtracted (i) the face value of Five9’s outstanding convertible notes, as of July 14, 2021, as provided by Five9 management and (ii) the value of Five9’s finance leases as of March 31, 2021 as reported on the Five9 10-Q filed April 29, 2021; and divided the resulting amount by the number of fully diluted shares of Five9 common stock outstanding as of July 14, 2021 (calculated utilizing the same methodology as used in the above discounted cash flow analysis). This analysis implied a range of values for Five9 common stock of approximately $116.87 to $224.63 per share, and implied exchange ratios based on the Zoom Class A common stock closing share price of $361.97 as of July 16, 2021, of 0.3229x to 0.6206x.

No company or transaction utilized in the selected transactions analysis is identical to Five9 or the merger. In evaluating the selected transactions, Qatalyst Partners made judgments and assumptions with regard to industry performance, general business, economic, market and financial conditions and other matters, many of which are beyond Five9’s control, such as the impact of competition on Five9’s business or the industry generally, industry growth and the absence of any material adverse change in Five9’s financial condition and prospects or the industry or in the financial markets in general, which could affect the public trading value of the companies and the aggregate value of the transactions to which they are being compared. Individual multiples or

-73-

mathematical analysis, such as determining the arithmetic mean, median, or the high or low, is not in itself a meaningful method of using selected transactional data. Because of the unique circumstances of each of these transactions and the merger, Qatalyst Partners cautioned against placing undue reliance on this information.

Miscellaneous

In connection with the review of the merger by the Five9 board, Qatalyst Partners performed a variety of financial and comparative analyses for purposes of rendering its opinion. The preparation of a financial opinion is a complex process and is not necessarily amenable to a partial analysis or summary description. In arriving at its opinion, Qatalyst Partners considered the results of all its analyses as a whole and did not attribute any particular weight to any analysis or factor it considered. Qatalyst Partners believes that selecting any portion of its analyses, without considering all analyses as a whole, could create a misleading or incomplete view of the process underlying its analyses and opinion. In addition, Qatalyst Partners may have given various analyses and factors more or less weight than other analyses and factors, and may have deemed various assumptions more or less probable than other assumptions. As a result, the ranges of valuations resulting from any particular analysis described above should not be taken to be Qatalyst Partners’ view of the actual value of Five9. In performing its analyses, Qatalyst Partners made numerous assumptions with respect to industry performance, general business, economic, market and financial conditions and other matters, many of which are beyond the control of Five9 and Zoom. Any estimates contained in Qatalyst Partners’ analyses are not necessarily indicative of future results or actual values, which may be significantly more or less favorable than those suggested by such estimates.

Qatalyst Partners conducted the analyses described above solely as part of its analysis of the fairness, from a financial point of view, of the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom), to such holders. These analyses do not purport to be appraisals or to reflect the price at which Five9 common stock or Zoom Class A common stock might actually trade or otherwise be transferable at any time.

Qatalyst Partners’ opinion and its presentation to the Five9 board was one of many factors considered by the Five9 board in deciding to approve the merger agreement. Consequently, the analyses as described above should not be viewed as determinative of the opinion of the Five9 board with respect to the exchange ratio to be received pursuant to, and in accordance with, the terms of the merger agreement by the holders of shares of Five9 common stock (other than Zoom or any affiliate of Zoom) or of whether the Five9 board would have been willing to agree to a different exchange ratio. The exchange ratio was determined through arm’s-length negotiations between Five9 and Zoom and was approved by the Five9 board. Qatalyst Partners provided advice to Five9 during these negotiations. Qatalyst Partners did not, however, recommend any specific exchange ratio to Five9 or that any specific consideration constituted the only appropriate consideration for the merger.

Qatalyst Partners provides investment banking and other services to a wide range of entities and individuals, domestically and offshore, from which conflicting interests or duties may arise. In the ordinary course of these activities, affiliates of Qatalyst Partners may at any time hold long or short positions, and may trade or otherwise effect transactions in debt or equity securities or loans of Five9, Zoom or certain of their respective affiliates. During the two-year period prior to the date of Qatalyst Partners’ opinion, no material relationship existed between Qatalyst Partners or any of its affiliates and Five9 or Zoom pursuant to which compensation was received by Qatalyst Partners or its affiliates; however, Qatalyst Partners and/or its affiliates may in the future provide investment banking and other financial services to Five9 or Zoom or any of their respective affiliates for which Qatalyst Partners would expect to receive compensation.

Under the terms of its engagement letter, Qatalyst Partners provided Five9 with financial advisory services in connection with the merger for which it will be paid an amount currently estimated at approximately $100 million (provided, that the final actual fee will be based on an average of the closing price of Zoom Class A Common Stock over ten (10) consecutive trading days up to and including the second trading day immediately preceding the closing of the merger, and, accordingly, the final fee may vary significantly from this estimate),

-74-

$250,000 of which was payable upon the execution of the engagement letter and $4 million of which was payable upon delivery of its opinion (regardless of the conclusion reached in the opinion), and the remaining portion of which will be paid upon, and subject to, consummation of the merger. Five9 has also agreed to reimburse Qatalyst Partners for its expenses incurred in performing its services. Five9 has also agreed to indemnify Qatalyst Partners and its affiliates, their respective members, directors, officers, partners, agents and employees and any person controlling Qatalyst Partners or any of its affiliates against certain liabilities, including liabilities under the federal securities laws, and expenses related to or arising out of Qatalyst Partners’ engagement.

Regulatory Approvals

U.S. Antitrust

Under the HSR Act and the rules and regulations promulgated thereunder, the merger may not be completed until Zoom and Five9 each files a notification and report form with the FTC and the DOJ, and the applicable waiting period has expired or been terminated. A transaction notifiable under the HSR Act may not be completed until the expiration of a 30-calendar-day waiting period following the parties’ filings of their respective HSR Act notification and report forms or the early termination of that waiting period. If the FTC or DOJ issues a request for additional information and documentary materials (which we refer to as a “Second Request”) prior to the expiration of the initial waiting period, the parties must observe a second 30-day waiting period, which would begin to run only after both parties have complied with the Second Request, unless the waiting period is terminated earlier or the parties agree with the FTC or DOJ to delay consummation of the merger for a specified period of time.

Zoom and Five9 each filed a Notification and Report Form with respect to the transaction with the FTC and DOJ on July 30, 2021. The waiting period with respect to the notification and report forms filed under the HSR Act is scheduled to expire at 11:59 p.m., Eastern Time, on August 30, 2021, unless a Second Request is issued or the waiting period is earlier terminated.

At any time before or after consummation of the transactions, notwithstanding the termination or expiration of the waiting period under the HSR Act, the FTC or the DOJ could take such action under the antitrust laws as either deems necessary under the applicable statutes, including seeking to enjoin the completion of the merger, seeking divestiture of substantial assets of the parties, or requiring the parties to license, or hold separate, assets, to modify or terminate existing relationships and contractual rights, or to impose a restriction, requirement or limitation on the operation of the business. At any time before or after the completion of the transactions, and notwithstanding the termination or expiration of the waiting period under the HSR Act, any state could also take such action under the antitrust laws as it deems necessary.

While the transaction is expected to close in the first half of calendar year 2022, it is not currently possible to predict with certainty how long it will take to obtain expiration or termination of the applicable waiting period under the HSR Act and there can be no assurance that a challenge to the transactions on antitrust grounds will not be made, or if such a challenge is made, what the result will be. The parties’ obligation to consummate the transaction is subject to certain conditions. See the section entitled “The Merger Agreement—Conditions to the Merger.”

Communications Approvals

Zoom and Five9 are subject to regulation by the FCC under the Federal Communications Act of 1934, as amended (which we refer to as the “Communications Act”). Five9 holds authorizations issued by the FCC to provide domestic and international telecommunications services. The FCC must approve the transfer of control of Five9 to Zoom as a result of the merger, and the applications are subject to public comment and possible opposition by third parties. Five9 also holds certificates and registrations issued by the CPUC and the GPSC (which we refer to as “PUCs”) and foreign bodies regulating telecommunications businesses. The PUCs require

-75-

formal applications for the transfer of Five9 in connection with the merger. Applications for state approvals are subject to public comment and possible opposition by third parties. In addition to these applications, Zoom and Five9 may file prior notifications of the merger in certain states and foreign jurisdictions where formal applications are not required, and some of these or other state commissions or foreign bodies could initiate proceedings investigating the merger. Under the Merger Agreement, it is a condition to each party’s obligations to effect the merger that all consents required to be obtained from the FCC and the PUCs in connection with the transactions contemplated by the merger agreement are obtained.

The applications for FCC consent were filed on July 30, 2021, a public notice of the filing of the application for consent to the transfer of Five9’s domestic Section 214 authorization and establishing a comment cycle was released on August 10, 2021, and a public notice of the filing of the application for consent to the transfer of the international Section 214 authorization held by Five9 and establishing a comment cycle was released on August 13, 2021. The application for CPUC consent was filed on July 30, 2021. The application for GPSC consent was filed on July 30, 2021. The timing or outcome of the communications approvals process cannot be predicted.

Other Regulatory Approvals

The merger is also conditioned on the expiration or termination of any applicable waiting period, or receipt of all requisite approvals, consents, waivers or clearances under applicable antitrust or competition laws in Russia. Zoom has made the requisite filings in this jurisdiction. Russian governmental agencies may impose a condition, restriction, qualification, requirement or limitation when it grants the necessary approvals and consents. Additionally, the merger is subject to certain other closing conditions as specified in the section entitled “The Merger Agreement—Conditions to the Merger.” While the transaction is expected to close in the first half of 2022, it is not currently possible to predict with certainty how long it will take to obtain all of the required regulatory approvals or whether such approvals will ultimately be obtained and there may be a substantial period of time between the approval by Five9 stockholders and the completion of the merger.

Although we expect that all regulatory clearances and approvals will be obtained, we cannot assure you that these regulatory clearances and approvals will be timely obtained, obtained at all or that the granting of these regulatory clearances and approvals will not involve the imposition of additional conditions on the completion of the merger, including the requirements to divest assets, or require changes to the terms of the merger agreement. These conditions or changes could result in the conditions to the merger not being satisfied.

Interests of Five9 Directors and Executive Officers in the Merger

In considering the recommendation of the Five9 board with respect to the merger proposal, the non-binding compensation advisory proposal and the adjournment proposal, Five9 stockholders should be aware that the directors and executive officers of Five9 have interests in the merger that may be different from, or in addition to, the interests of Five9 stockholders generally. The members of the Five9 board were aware of and considered these interests, among other matters, in evaluating and negotiating the merger agreement, in approving the merger agreement and in determining to recommend that Five9 stockholders approve the merger proposal.

Treatment of Director and Executive Officer Equity Awards in the Merger

The Five9 equity awards held by Five9’s non-employee directors and executive officers immediately before the effective time will be treated as described below in the section entitled “The Merger Agreement—Treatment of Five9 Equity Awards.” As described in that section, equity awards held by Five9’s non-employee directors will fully vest in connection with the closing of the merger.

As described below in the section entitled “—New Compensation Arrangements with Zoom,” pursuant to his employment offer letter with Zoom, following the closing Mr. Trollope’s Five9 options and Five9 RSU awards that are assumed and converted into adjusted options and adjusted RSU awards, respectively, will not vest

-76-

according to their existing schedule, but instead shall vest in full on the earlier to occur of (i) the first anniversary of the closing date, subject to Mr. Trollope’s continued service, or (ii) Mr. Trollope’s termination of employment without cause.

As described below in the section entitled “—Change of Control Severance Benefits,” pursuant to the terms of the severance plan (as defined below), outstanding and unvested Five9 equity awards will vest in full upon a qualifying termination of employment that occurs during the period beginning three months before and ending 12 months after the closing date.

For an estimate of the amounts that would be payable to each of Five9’s named executive officers on settlement of their unvested Five9 equity awards, see the section entitled “—Merger-Related Compensation—Golden Parachute Compensation” below. All of Five9’s executive officers are named executive officers. The estimated aggregate amount that would be payable to Five9’s nine non-employee directors in settlement of their 14,677 Five9 RSU awards that are currently outstanding is $2,793,180. None of Five9’s non-employee directors hold unvested Five9 options. The amounts in this paragraph are determined using a per share price of Five9 common stock of $190.31 (the average closing price of a share of Five9 common stock over the first five business days following the first public announcement of the merger), and assume that the closing date occurs on August 2, 2021.

Retention RSU Awards

In connection with entering into the merger agreement, Five9 has granted retention awards in the form of Five9 RSU awards to Messrs. Zwarenstein, Burkland, and Welch (which we refer to as the “Five9 retention awards”). Each Five9 retention award will vest as to one-third of the underlying units on the closing date, the 9-month anniversary of the closing date, and the 18-month anniversary of the closing date, subject to the executive’s continued employment through the applicable vesting date. The Five9 retention awards will be treated like other Five9 RSU awards in connection with the transaction as described below in the section entitled “The Merger Agreement—Treatment of Five9 Equity Awards.” The Five9 retention awards are also subject to accelerated vesting as described below in the section entitled “—Change of Control Severance Benefits” pursuant to the terms of the severance plan.

Change of Control Severance Benefits

Each of Five9’s executive officers participates in Five9’s 2019 Key Employee Severance Benefit Plan (which we refer to as the “severance plan”) that provides for severance and accelerated vesting benefits in connection with certain terminations of employment. In connection with the merger agreement and contingent upon the closing of the merger, Rowan Trollope has entered into an employment offer letter with Zoom pursuant to which Mr. Trollope will receive certain severance and accelerated vesting benefits and has waived any severance or benefits to which he would have otherwise been entitled under the severance plan and has acknowledged and agreed that his acceptance of the employment offer letter and his terms and conditions of employment do not constitute a “constructive termination” or any other triggering event under his existing agreements with Five9. However, Mr. Trollope will remain eligible for benefits under the severance plan until his employment offer letter with Zoom is effective upon the closing of the merger. For more details, see the section entitled “—New Compensation Arrangements with Zoom.”

Under the severance plan, if an executive’s employment with Zoom is terminated by Zoom (or by Five9 during the period beginning three months before the change in control) without cause (other than due to death or disability) or by the executive pursuant to a “constructive termination” (as defined in the severance plan), and such qualifying termination occurs during the period beginning three months before and ending 12 months after a change in control of Five9, then the executive is eligible to receive (as applicable):

-77-

Each executive must execute and deliver an effective release of claims and continue to comply with any applicable restrictive covenants in order to receive the payments and benefits provided for under the severance plan.

In addition, in connection with entering into the merger agreement, the Five9 board adopted a policy providing that if an employee’s (including an executive officer) employment terminates due to death or disability at any time following a change in control of Five9, then the vesting of all unvested and outstanding equity awards that such employee held as of immediately before the change in control (as assumed, substituted, or converted in the change in control) shall fully accelerate as of immediately before the employee’s termination of employment.

Cash Incentive Bonuses and Other Misc. Payments

The ancillary agreements under the merger agreement provide that if the closing of the merger occurs in 2021, then, effective the day before the closing date, Five9 will pay to its then-current employees who participate in a periodic cash incentive plan for fiscal year 2021 (including Five9’s Executive Incentive Compensation Plan, in which Five9’s executive officers participate) a bonus for the applicable performance period in which the closing date occurs, calculated based on 120% of target performance and prorated for the portion of the applicable performance period that has elapsed as of the closing date; provided, however, that if the closing occurs in 2022, Zoom shall, or shall cause Five9 to, pay its then-current employees who participate in a periodic cash incentive plan for fiscal year 2021 (including Five9’s Executive Incentive Compensation Plan, in which Five9’s executive officers participate), a cash payment equal to the prorated portion of the applicable bonus prorated from the end of the calendar quarter immediately preceding the closing through the end of the calendar quarter in which the closing occurs (regardless of whether the applicable performance period is quarterly), to the extent such portion is unpaid as of the closing, determined at a performance level of 120% of target performance.

In lieu of assuming the obligations to provide health benefits (or a yearly cash payment) under Michael Burkland’s Chairman of the Board Agreement with Five9, Zoom will pay to Mr. Burkland a $450,000 lump sum cash payment within 10 days following the closing of the merger.

Sections 280G and 4999 of the Code

If Five9 determines that an executive officer may become subject to an excise tax under Section 4999 of the Code in relation to “parachute payments” under Section 280G of the Code, and if the closing of the merger will occur in 2022, then in order to mitigate or eliminate such excise taxes, Five9 has the discretion under the merger agreement, in consultation with Zoom, to accelerate into calendar year 2021 the vesting of Five9 RSU awards that would otherwise vest before the closing, and accelerate and pay 2021 bonuses in calendar year 2021 based on a good faith estimate of achievement of actual performance. Additionally, if the foregoing mitigation actions are insufficient to fully mitigate the exposure of potential excise taxes, Five9 may (or in the case of Mr. Trollope, shall) pay amounts to the affected executive officer that are sufficient to gross them up for any such excise taxes (including any excise taxes on such gross-up payments); provided that, except to the extent payments or benefits under a compensatory arrangement with Zoom result in such excise taxes, Five9’s gross-up obligation cannot exceed $7.5 million in the aggregate.

Indemnification and Insurance

Pursuant to the terms of the merger agreement, directors and executive officers of Five9 will be entitled to certain ongoing indemnification and coverage under directors’ and officers’ liability and fiduciary liability

-78-

insurance policies following the merger. For more details, see the section entitled “—Indemnification and Insurance.”

New Compensation Arrangements with Zoom

In connection with the merger agreement and contingent upon the closing of the merger, Rowan Trollope has entered into an employment offer letter with Zoom pursuant to which Mr. Trollope will serve as a president of Zoom and Chief Executive Officer of Five9 following the closing. Under the offer letter, Mr. Trollope will be entitled to an annual base salary of $600,000, and will have a target annual bonus opportunity equal to 100% of his annual base salary (with a maximum potential payout of 120% of his annual base salary). Additionally, effective as of the closing, Mr. Trollope will be granted an award of Zoom restricted stock units (which we refer to as a “Zoom RSU award”) with a grant date value of $40 million. The Zoom RSU award will vest as to 50% of the underlying units on the second anniversary of the closing date, and as to the remaining 50% of the underlying units on the third anniversary of the closing date, subject to Mr. Trollope’s continued employment.

The offer letter also provides that, notwithstanding anything to the contrary in the merger agreement, Mr. Trollope’s Five9 options and Five9 RSU awards that are assumed and converted into adjusted options and adjusted RSU awards, respectively, will not vest according to their existing schedule, but instead shall vest in full on the earlier to occur of (i) the first anniversary of the closing date, subject to Mr. Trollope’s continued service, or (ii) Mr. Trollope’s termination of employment without cause.

Additionally, if Zoom undergoes a change in control and Mr. Trollope’s employment is terminated without cause or he resigns for good reason (each as defined in the offer letter) upon or within one year following the date of the change in control of Zoom, he will be eligible for the following:

Mr. Trollope must execute and deliver an effective release of claims and continue to comply with the terms of the offer letter in order to receive the payments and benefits set forth above (other than the equity acceleration benefits).

Merger-Related Compensation

This section sets forth the information required by Item 402(t) of Regulation S-K regarding the compensation for each of Five9’s named executive officers that is based on or otherwise relates to the merger and that will or may become payable to the named executive officers at the completion of the merger or on a qualifying termination of employment upon or following the consummation of the merger. This compensation is referred to as “golden parachute” compensation by the applicable SEC disclosure rules. The “golden parachute” compensation payable to these individuals is subject to a non-binding advisory vote of Five9’s stockholders. The “named executive officers” are the individuals listed as such in Five9’s most recent annual proxy statement.

The table below assumes that:

-79-

For purposes of the footnotes to the table below, “single trigger” refers to benefits that arise solely as a result of the completion of the merger, and “double trigger” refers to benefits that require two conditions, which are the completion of the merger (or in the case of Mr. Trollope, a change in control of Zoom) and a qualifying termination. Payments of double trigger benefits are contingent on the named executive officer delivering an effective release of claims in favor of Five9 (except Mr. Trollope, who is not eligible for such severance benefits following the closing) and continuing to comply with any applicable restrictive covenants, as described above in the section entitled “ —Change of Control Severance Benefits.”

Golden Parachute Compensation

-80-

The following table quantifies each separate form of cash compensation included in the aggregate total reported in the column:

The value of the first tranche (one-third) of the Five9 retention awards to Messrs. Zwarenstein, Burkland, and Welch are single trigger, in that they will vest upon the effective time. The remaining amounts (including the remaining tranches (two-thirds) of the Five9 retention awards) are double trigger benefits, in that they will vest only if the named executive officer experiences a qualifying termination of employment following the effective time (or otherwise vest in accordance with their terms).

The following table quantifies the value of the unvested Five9 options and Five9 RSU awards included in the aggregate total reported in the column, which are separately identified as single trigger or double trigger benefits. The estimated value of unvested Five9 options in the table below equals the number of net shares underlying the option, multiplied by $190.31. The estimated value of Five9 RSU awards in the table below equals the number of shares of Five9 common stock underlying the award, multiplied by $190.31.