X0306 4 2015-03-15 0001463172 Zendesk, Inc. ZEN 0001605957 McDermott Adrian 1019 MARKET STREET SAN FRANCISCO CA 94103 1 SVP of Product Development Common Stock 2015-03-15 4 M 0 2604 A 85381 D Common Stock 2015-03-15 4 F 0 963 22.54 D 84418 D Common Stock 2015-03-16 4 M 0 7294 .11 A 91712 D Common Stock 2015-03-16 4 S 0 7294 22.5402 D 84418 D Restricted Stock Unit 2015-03-15 4 M 0 2604 D 2022-02-04 Common Stock 2604 122396 D Stock Option (Right to Buy) .11 2015-03-16 4 M 0 7294 0 D 2020-09-09 Common Stock 7294 223892 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 $22.23 to $22.78 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. 1/4th of the shares subject to the option vested on July 26, 2011 and 1/48th of the shares subject to the option shall 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. /s/ John Geschke, Attorney-in-Fact for Adrian McDermott 2015-03-17