Key blocked

A blocked Office 2016 key cannot be released through this forum or by repeating automated telephone activation; reinstall from the Microsoft account linked to the purchase, and if activation still reports “Key blocked,” contact Microsoft Support for a key-status review.

Reinstall through the linked Microsoft account

A previously redeemed product key should not be redeemed again:

1. Open account.microsoft.com.
2. Sign in with the Microsoft account originally used to redeem or purchase Office.
3. Locate Office Professional 2016 and select Install.
4. After installation, open Word or Excel and sign in with that same account.

The message “This product key has already been used” can simply mean that the key was previously redeemed and is now associated with the Microsoft account; installation should then be performed from the account instead of by entering the key again.^1^

If the account installation still says “Key blocked”

Use the Contact support option on Microsoft’s product-key page and request review of the blocked Office 2016 key.^1^ Microsoft Learn Q&A participants cannot inspect activation records, validate an Installation ID, or remove a server-side block.

Be ready to identify:

• The exact edition: Office Professional 2016
• Where and when it was purchased
• The Microsoft account associated with it, if applicable
• The product key and purchase evidence, provided only through Microsoft’s private support process

If the key was purchased separately from a third-party seller, Microsoft’s guidance is to contact that seller and request a refund when the key has stopped working or was blocked. Such keys may have been unauthorized or resold.^1^

Office Professional is licensed for one computer. A maximum-activation error can also occur on the same computer after a hardware change; Microsoft documents telephone activation for eligible transfers, but the automated system has already rejected this Installation ID, so the next step is support review rather than repeating that process.^2^

Office 2016 has reached end of support, although Microsoft’s product-key page still directs users with key problems to seller or Microsoft Support assistance.^1^

For privacy, remove the Installation ID from the public post. Do not publish the product key, purchase details, or Microsoft account address.

References

1. Where to enter your Office product key
2. Activate Office after reinstalling or installing on a different device | Microsoft Support