How to recuparate Office Product Key if during registration the wrong email was entered

The product key is now tied to the Microsoft account that was entered during the first activation attempt. Once a key is redeemed and associated with a Microsoft account, it cannot be moved or reassigned through self-service.

Because the wrong email (Microsoft account) was used and the key is already marked as redeemed, this cannot be fixed by re-entering the key on Office.com/setup or Microsoft365.com/setup. The next step is to contact Microsoft Support so an agent can review the activation history and ownership and advise on possible recovery options.

Use the official Microsoft support channel and provide:

• The 25-character product key.
• Proof of purchase.
• The incorrect email address that was entered (if known).
• The correct Microsoft account that should own the license.

If the product key was purchased from a third-party retailer and support confirms that the key is already associated with another account in a way that cannot be corrected, contact the retailer as well to request resolution or a replacement.

References:

• "This product key has already been used" error in Office
• Get help with product key errors on Office.com/setup
• Office product key errors ERR_MISSING_PARTNUMBER or ERR_INVALID_TOKEN
• How can I install Home Office 2024 with my Microsoft Account with your directions. - Microsoft Q&A
• Theft/Fraud Associated with my Office Product Key. - Microsoft Q&A
• Unable to Redeem MS Office2024 Professional Plus Product Key - Microsoft Q&A
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