Microsoft documentation states that Office apps using an expiring digital certificate for licensing validation will enter reduced functionality mode after July 13, 2026, unless updated to builds 16.83 (macOS) or 2.93 (iOS) requiring macOS 12 or iOS 17. [1] The minimum builds exclude Office 2019, which is capped below the threshold with no resolution path per support notes. [3]

Microsoft's June 2023 end-of-support page stated Office 2019 for Mac apps would continue to function after October 10, 2023 support end; the May 2026 revision removed that clause while retaining data access language and adding references to Microsoft 365 products. [2][4] Administrator docs confirm older perpetual versions lack the renewed certificate. [1]

Office 2021 for Mac reaches support end October 13, 2026 under the same one-time purchase model announced in 2018 and 2021 launch posts, with no on-premises feature updates promised. [5][7] Related Microsoft lifecycle pages and prior Windows perpetual releases show parallel certificate-based validation patterns.