Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Hello @Daniel Mendez
The important distinction here is between the account signed into Office and the account that owns the Office 2021 license.
If you redeemed or activated the one-time-purchase Office 2021 license using your Microsoft account, simply signing out and signing in with your daughter's account doesn't transfer ownership of the license. Microsoft states that Office remains licensed to the account originally used to activate it.
You can sign your personal account out of the Mac by opening an Office application and selecting Word/Excel → Sign Out, then quit all Office applications. This will prevent your daughter from accessing your connected Office services such as OneDrive.
If your daughter already has her own Microsoft 365/Office license through college, you can use Microsoft's Office License Removal Tool for Mac, then open Office and activate it using her school/Microsoft account.
If she doesn't have her own license and your goal is to transfer your Office 2021 license permanently to her account, that's different. Microsoft generally permits transferring Office 2021 to another computer you own, but transferring the license to another person has additional licensing restrictions; Microsoft specifically provides an account-transfer process for users in the EEA. In that situation, I'd contact Microsoft Support before attempting to change the license ownership.
One other point: the name shown as the document author doesn't have to be the account that purchased Office. Your daughter can configure her own author information in Word, so she doesn't need access to your Microsoft account simply to have her name appear as the author.
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