Need Help Reinstalling my one time Subscription purchase of Office Home & Business 2021

Install Office 2021 directly from Microsoft—not from the Mac App Store—and activate it with the Microsoft account that owns your Office Home & Business 2021 license.

Reinstall the correct Mac version

Mac App Store copies of Word and Excel require Microsoft 365 for editing and cannot be activated with a perpetual Office license. Microsoft provides this direct installer for Office 2021 for Mac: Download the Office 2021 for Mac installer.^1^

1. Quit Word, Excel, PowerPoint, and Outlook.
2. Open Finder → Applications.
3. Control-click each installed Microsoft Office application and select Move to Trash. This is particularly important if the applications were obtained from the Mac App Store.
4. Download the installer using the direct Microsoft link above.
5. Open Finder → Downloads, then double-click the downloaded .pkg.
6. Select Continue → Agree → Install. If only Word and Excel are needed, select Customize and clear the other applications.
7. Open Word or Excel and select Get Started.
8. Sign in with the same personal Microsoft account under which Office Home & Business 2021 appears in Products you’ve purchased. The account—not a new Microsoft 365 purchase—activates the perpetual license.^2^

The installer package can carry Microsoft 365 branding because Microsoft uses common Office application packages; the license selected after sign-in determines whether the installation operates as Microsoft 365 or Office 2021.

If Excel still asks for Microsoft 365

Your macOS Golden Gate 27 version is within the supported macOS range. Microsoft’s current remediation for Office 2021 entering read-only or “reduced functionality” mode is to update Office and then refresh the sign-in:^3^

1. Open Word or Excel.
2. Select Help → Check for Updates.
3. In Microsoft AutoUpdate, select Update All.
4. When updating finishes, quit the application completely with Command+Q.
5. Reopen it, sign out in its account settings, and sign back in with the account holding Office 2021.
6. Open Excel → About Microsoft Excel and verify that the displayed license is Office 2021, rather than Microsoft 365.

If the wrong license remains cached

Remove the stored licenses only if reinstalling, updating, and signing back in still leave Office asking for Microsoft 365. Have the Office 2021 account credentials available first; this process removes locally stored Office licenses, not the purchase attached to the account.^4^

1. Download Microsoft’s Office license removal tool.
2. Open the downloaded .pkg. If macOS blocks it, Control-click it and select Open.
3. Select Continue → Install and enter the Mac administrator password.
4. After the tool reports success, open Word or Excel.
5. Sign in with the Microsoft account associated with Office Home & Business 2021 and select that one-time license if a license-selection screen appears.
6. Restart the Mac and test saving a document.

Office 2021 support ended on October 13, 2026. The applications may continue working, but Microsoft no longer provides Office 2021 security updates, bug fixes, or technical support; end of support does not itself convert the perpetual license into a Microsoft 365 subscription.^5^

References

1. Microsoft Office activation and the Mac App Store | Microsoft Support
2. [Office for Mac 2021](https://support.microsoft.com/office/lifecycle/officeinstall/download-and-install-or-reinstall-office-2021-office-2019-or-office-2016)
3. Update Microsoft 365 or Office on your macOS or iOS device | Microsoft Support
4. How to remove Office license files on a Mac | Microsoft Support
5. End of support for Office 2021 | Microsoft Support