Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
This usually happens when the Mac is using the wrong Office build or stale license data, not because the perpetual Office 2021 license was converted into Microsoft 365.
A supported recovery path is:
- Confirm the purchase is associated with the correct account
- If the Office 2021 purchase was redeemed to a Microsoft account, sign in to that same account and verify the one-time purchase appears under Services and Subscriptions.
- For one-time purchases bought at retail or online, the product key must be redeemed once at
https://office.com/setupso the product is linked to the account.
- Remove the current Office apps from the Mac
- Close Word, Excel, PowerPoint, and Outlook.
- In Finder > Applications, locate the Office apps, control-click each one, and choose Move to Trash.
- Reinstall Office directly from Microsoft, not from the Mac App Store
- The Mac App Store build is a known source of activation issues for perpetual licenses.
- Microsoft provides direct installers for perpetual Mac releases. Install the Office 2021 for Mac package from Microsoft and complete setup.
- The installer package name can still reference Microsoft 365 branding. That does not by itself mean the install requires a subscription. Activation determines whether the apps run under a Microsoft 365 subscription or a perpetual Office 2021 license.
- Activate with the perpetual license
- After installation, open an Office app and sign in with the Microsoft account associated with the Office 2021 purchase if prompted.
- If the license is recognized, the apps should activate and allow editing and saving again.
- If the problem continues, clear license data again and reactivate
- Microsoft’s Mac license removal tool removes all Microsoft 365 for Mac licenses from the device.
- Important: have the correct account credentials ready before doing this, because reactivation is required afterward.
- Check which license the app is using
- On Mac, open an Office app and go to <App Name> in the menu bar > About to verify which version/license is being used.
If the apps still open in reduced functionality after reinstalling directly from Microsoft, the most likely remaining causes in the available guidance are:
- the wrong Microsoft account is being used for activation, or
- the Mac is still holding incorrect license data and needs the license removal tool followed by reactivation.
- How to remove Office license files on a Mac | Microsoft Support
- Microsoft Office activation and the Mac App Store | Microsoft Support
- [Need help?](https://support.microsoft.com/office/lifecycle/officeinstall/download-install-or-reinstall-microsoft-365-or-office-2024-on-a-pc-or-mac)
- [Activation](https://support.microsoft.com/microsoft-365-activation-licensing/what-to-try-if-you-can-t-install-or-activate-office-for-mac)
- Why do I need an account to sign in to Microsoft 365 or Office? | Microsoft Support