“This code has already been redeemed” Microsoft Error Message
This is what to do if you see a “This code has already been redeemed” error message on the Microsoft redemption page.
Check your services & subscriptions page
Sometimes the Microsoft redemption page glitches out during redemption and states the key has been redeemed, when it’s actually been applied to your account.
Please check the services & subscriptions page of your Microsoft account to see if the key has already been applied and the software provided to your account here: https://account.microsoft.com/services