if I buy a new mac air, can I transfer my life-time-usage subscription of office to the new mac air?

Yes—if the “lifetime” product is a one-time purchase of Office for Mac, it can be moved to another Mac that belongs to the same owner.

Key points:

• A one-time purchase of Office for Mac is installed on one Mac at a time.
• Office 2024 or Office 2021 can be transferred to another computer owned by the same person, but not more than once every 90 days, except in the case of hardware failure.
• When transferring, the software must be removed from the old computer and no copies may be retained.

If moving from an older Mac Office version to a newer purchase:

1. On the new Mac, install Office and sign in with the account associated with the Office purchase.
2. If replacing Office 2016 for Mac or Office 2019 for Mac with a newer version, remove the old license with the License Removal Tool.
3. Open any Office app, then select Help > Check for Updates.

Important:

• The Mac App Store versions of Word, Excel, and PowerPoint require a Microsoft 365 subscription to activate and are not compatible with Office 2019 licenses.
• A one-time purchase is different from Microsoft 365. Microsoft 365 is a subscription and includes ongoing updates; a one-time purchase does not include upgrade rights to future major versions.

• Transfer your Office license to another device or another person
• End of support for Office 2019 for Mac | Microsoft Support
• End of support for Office 2016 for Mac | Microsoft Support
• Microsoft Office and the Mac App Store | Microsoft Support
• Office 2021 and Office LTSC for Windows and Mac FAQ | Microsoft Support