office 2021

Reinstall Office 2021 from the Microsoft account associated with your product key; if the key has never been redeemed, redeem it first to create that association.

If you previously redeemed the key

1. Open the Microsoft account dashboard.
2. Sign in with the same Microsoft account used when Office 2021 was originally activated.
3. Select Office apps, locate Office 2021, and select Install.^1^
4. On your Mac, open Finder → Downloads, then double-click the downloaded installer package.
5. Select Continue → Agree → Install. Enter your Mac login password if requested, and select Close when installation finishes.
6. Open Launchpad → Microsoft Word, select Get Started, and sign in with the same Microsoft account to activate Office.^1^

You normally redeem a retail product key only once. After redemption, the Microsoft account—not repeated key entry—is used to reinstall and activate Office.

If the key was never redeemed

1. Go to https://office.com/setup.
2. Sign in with the Microsoft account you want linked to Office.
3. Enter the 25-character product key.
4. After redemption, return to the Microsoft account dashboard, select Office apps → Office 2021 → Install, and complete the Mac installation above.^1^

If Office 2021 is missing from the account

Try any other Microsoft account that may have been used for the original redemption. The license must appear under the account associated with that key; redeeming an already-used key again will not move it to another account.

If this was a Workplace Discount Program purchase, check the Microsoft account’s Services & subscriptions page using your personal Microsoft account rather than your work email. Purchases through that program can have a different reinstall process.^2^

References

1. Download and install or reinstall Office 2021, Office 2019, or Office 2016
2. Install or reinstall Office or Microsoft 365 through Microsoft Workplace Discount Program