X0306 4 2014-12-23 0001463172 Zendesk, Inc. ZEN 0001601008 Geschke John 1019 MARKET STREET SAN FRANCISCO CA 94103 1 SVP, GC and Secretary Common Stock 2014-12-23 4 M 0 23500 2.30 A 23500 D Common Stock 2014-12-23 4 S 0 23500 24.658 D 0 D Stock Option (Right to Buy) 2.30 2014-12-23 4 M 0 23500 0 D 2022-07-17 Common Stock 23500 218500 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 $24.53 to $24.8425 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. 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 2014-12-24