X0306 4 2021-07-22 false 0001724570 DATTO HOLDING CORP. MSP 0001828582 MCCHORD AUSTIN WILLIAMS 101 MERRITT 7 NORWALK CT 06851 true false false false Common Stock 2021-07-22 4 S false 17499.00 27.06 D 6555588.00 D Common Stock 2021-07-23 4 S false 10911.00 27.05 D 6544677.00 D The sale reported in this Form 4 was effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on June 14, 2021. This transaction was executed in multiple trades at prices ranging from $27.00 to $27.19 per share. The price reported reflects the weighted average sale price. Upon request by the Issuer, any security holder of the Issuer or the staff of the SEC, the Reporting Person undertakes to provide full information regarding the number of shares sold at each separate price within the range set forth in this footnote. This transaction was executed in multiple trades at prices ranging from $27.00 to $27.21 per share. The price reported reflects the weighted average sale price. Upon request by the Issuer, any security holder of the Issuer or the staff of the SEC, the Reporting Person undertakes to provide full information regarding the number of shares sold at each separate price within the range set forth in this footnote. /s/ Adam Collicelli, by Power of Attorney 2021-07-26