Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Office 2021 for Mac is a perpetual license, but support ended on October 13, 2026. After end of support, Microsoft no longer provides updates or technical support for Office 2021, and newer app versions can cause licensing or reduced-functionality issues.
For this specific Mac issue, the supported facts in the available guidance are:
- Office 2021 can still be installed from the Microsoft account page under purchased products.
- Office 2021 for Mac is supported only on one of the three most recent macOS versions.
- Starting with newer Office for Mac builds, incorrect or unsupported license/update state can put apps into read-only or limited functionality mode.
- In similar reported cases for Office 2021 on Mac after the October 2026 support change, the accepted resolution was:
- uninstall the current Office apps
- install an older 16.114 build
- open an Office app
- go to Help > Check for Updates
- in Microsoft AutoUpdate, turn off Automatically keep Microsoft apps up to date
If the current install from the Microsoft account page keeps reinstalling the newer build and asks for activation again, the practical path is:
- Uninstall the current Office for Mac apps.
- Install this older build:
-
https://res.public.onecdn.static.microsoft/mro1cdnstorage/C1297A47-86C4-4C1F-97FA-950631F94777/MacAutoupdate/Microsoft_365_and_Office_16.114.26101123_BusinessPro_Installer.pkg?atp=ets
-
- Open Word or Excel.
- Select Help > Check for Updates.
- In Microsoft AutoUpdate, clear Automatically keep Microsoft apps up to date, then confirm Turn Off.
If that build does not work, similar accepted guidance also referenced 16.113 as an alternative older build:
-
https://res.public.onecdn.static.microsoft/mro1cdnstorage/C1297A47-86C4-4C1F-97FA-950631F94777/MacAutoupdate/Microsoft_365_and_Office_16.113.26100421_Installer.pkg?atp=ets
Important:
- Turning off AutoUpdate avoids reinstalling the newer build that is triggering the license problem.
- Office 2021 is out of support, so this is a workaround rather than a supported long-term fix.
- If macOS is not within the three most recent versions, Office 2021 for Mac is not in a supported OS configuration.
- End of support for Office 2021 | Microsoft Support
- Office 2021 and Office LTSC for Windows and Mac FAQ | Microsoft Support
- Update Microsoft 365 or Office on your macOS or iOS device | Microsoft Support
- Set Office License Info for updates for Microsoft AutoUpdate
- Office Home & Student 2021 (one-time purchase) will not activate on Mac - "No License Found" - Microsoft Q&A
- Office 2021 not working, says my license isn't activated - Microsoft Q&A
- Office 2021 Home & Student license suddenly stopped working on Mac - Microsoft Q&A
- Office 2021, release of 16.114.1- License Removed - Microsoft Q&A
- Office for Mac 2021 stopped working - Microsoft Q&A