Microsoft Office 2021 for Mac has reached end of support on October 14, 2026, but you still can keep using the software.

MAU 2.0 – Microsoft Auto Update will continue to update the software even though it is not able to work based on the Microsoft Office 2021 License file.

Two things you need to do

1. Go into Settings, General, Login Items & Extensions and turn off Microsoft Auto Update
2. Go to the folder /Library/Application Support/Microsoft and trash MAU 2.0 folder

This will stop the Microsoft Auto Update from updating Microsoft Office to a unlicensed copy.

If you have a Mac that has already updated to Microsoft Office 16.114.1 or later that are not supported by the license.  Trash each Excel, OneNote, Outlook, PowerPoint and Word. Download https://res.public.onecdn.static.microsoft/mro1cdnstorage/C1297A47-86C4-4C1F-97FA-950631F94777/MacAutoupdate/Microsoft_365_and_Office_16.114.26101123_Installer.pkg  installer package for Microsoft Office 2021 version 16.114. Install this package to get the last version of Office 2021.  Make sure the MAU 2.0 from step 2 above is not located.  If you have MAU 2.0 each application will keep prompting you to update to the latest edition.