X0306 4 2014-12-22 0001463172 Zendesk, Inc. ZEN 0001605957 McDermott Adrian 1019 MARKET STREET SAN FRANCISCO CA 94103 1 SVP of Product Development Common Stock 2014-12-22 4 M 0 48634 .11 A 131411 D Common Stock 2014-12-22 4 S 0 48634 24.5308 D 82777 D Common Stock 2014-12-23 4 M 0 1352 .11 A 84129 D Common Stock 2014-12-23 4 M 0 100 6.24 A 84229 D Common Stock 2014-12-23 4 M 0 417 9.52 A 84646 D Common Stock 2014-12-23 4 S 0 1869 25.00 D 82777 D Stock Option (Right to Buy) .11 2014-12-22 4 M 0 48634 0 D 2020-09-09 Common Stock 48634 356348 D Stock Option (Right to Buy) .11 2014-12-23 4 M 0 1352 0 D 2020-09-09 Common Stock 1352 354996 D Stock Option (Right to Buy) 6.24 2014-12-23 4 M 0 100 0 D 2023-05-03 Common Stock 100 486800 D Stock Option (Right to Buy) 9.52 2014-12-23 4 M 0 417 0 D 2024-02-13 Common Stock 417 245833 D This transaction was effected pursuant to a Rule 10b5-1 trading plan adopted by the Reporting Person. The sale price reported in column 4 of Table 1 represents the weighted average sale price of the shares sold ranging from $24.31 to $24.73 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. 1/4th 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. The option is immediately exercisable as of the grant date. 1/60th of the shares vest monthly after the vesting commencement date of April 23, 2013, 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 Issuer should the Reporting Person cease to provide continuous service. The option is immediately exercisable as of the grant date. 1/60th of the shares vest monthly after the vesting commencement date of February 13, 2014, 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 Issuer should the Reporting Person cease to provide continuous service. /s/ John Geschke, Attorney-in-Fact for Adrian McDermott 2014-12-24