X0306 4 2015-03-15 0001463172 Zendesk, Inc. ZEN 0001601008 Geschke John 1019 MARKET STREET SAN FRANCISCO CA 94103 1 SVP, GC and Secretary Common Stock 2015-03-15 4 M 0 235 A 235 D Common Stock 2015-03-15 4 F 0 122 22.54 D 113 D Common Stock 2015-03-17 4 M 0 9220 2.30 A 9333 D Common Stock 2015-03-17 4 S 0 9220 22.1035 D 113 D Restricted Stock Unit 2015-03-15 4 M 0 235 D 2022-02-04 Common Stock 235 11065 D Stock Option (Right to Buy) 2.30 2015-03-17 4 M 0 9220 0 D 2022-07-17 Common Stock 9220 163180 D Restricted stock units convert into common stock on a one-for-one basis. Represents the number of shares withheld by the Issuer in satisfaction of tax withholding obligations in connection with the vesting of the restricted stock units listed in Table II. Such withholding is mandated by an election of the Issuer made in advance and does not represent a discretionary trade by the reporting person. This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. This sale price represents the weighted average sale price of the shares sold ranging from $21.76 to $22.60 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price. 1/48th of the shares issuable pursuant to the restricted stock unit shall vest monthly after the vesting commencement date of February 15, 2015, subject to the Reporting Person's continuous service to the Issuer on each such date. Unvested shares are subject to acceleration upon the occurrence of certain events. The price in column 8 of Table II is $0. The option is immediately exercisable as of the grant date. 1/4th of the shares vested on July 9, 2013 and 1/48th of the shares vest monthly thereafter, subject to the Reporting Person's continuous service to the Issuer on each such date. Unvested shares are subject to acceleration upon the occurrence of certain events. Unvested shares exercised are subject to a right of repurchase in favor of the Company should the Reporting Person cease to provide continuous service. /s/ John Geschke 2015-03-17