Redeemed Gifted Game Code; Microsoft Account Says Activation Was Successful, yet Can't...

When my friend tries to activate the gift code, it says "This code can't be redeemed. It was purchased in a different region from your account."

It sounds as though they gifted you the console version of the game, not the PC version, so yes, it would only work on an Xbox since that game is not a Play Anywhere title. Unfortunately, since the code has been redeemed, there's nothing else that can be done.

Ah figures, worth a shot. Is there a way to tell the difference prior to redemption for future reference?

The £10 must be either on a card that says "Xbox Gift Card £10" or you must purchase an Xbox digital gift card code on Amazon for £10 that you redeem here:
https://redeem.microsoft.com/enter

You can't redeem Amazon gift cards or currency in Amazon accounts for currency in your Microsoft/Xbox account - you must buy an Xbox Gift Card (or code) with that money on it.

Hi Ivan,

Thank you for coming to the Xbox forums.

When you buy a gift card from a retailer, the card becomes activated once they scan the card's bar code. If you're getting an error message that the code is not activated, you may just need to wait a few hours, up to 24 hours sometimes. If you haven't done
so, I recommend also trying to redeem the code online as well as from the console. If the code hasn't been activated, return it to the place where it was purchased and ask for them to activate it so it can be redeemed. Make sure to take your proof of purchase
with you.

Please review this support article
"Redeem a gift card or code to your Microsoft account" for more information on how to redeem a gift card and what to do if there is an error.