"This code isn't valid in your region"
The card and your Microsoft account are set to different countries. Redeem it on an account from the card's country.
Redeem guide
Xbox and Microsoft gift cards feed the same Microsoft account balance — here are the three places to enter the code.

Quick answer
Go to redeem.microsoft.com, sign in with the Microsoft account you use on Xbox, enter the 25-character code and confirm. On the console, open the Microsoft Store and choose Redeem (or "Use a code"). The balance pays for games, add-ons and Game Pass in the Xbox and Microsoft stores.
Buy an Xbox Gift Card with cryptoThe short address microsoft.com/redeem leads to the same page. Works on a computer or a phone.
Use the Microsoft account that is signed in on your console or PC — the balance lands on that account only.
Type or paste the code from your email; hyphens are added for you. Select Next.
Microsoft shows what the code adds (balance or membership time). Select Confirm — it is available on Xbox and in the Microsoft Store right away.
Press the Xbox button, open the Microsoft Store, then choose Redeem (or "Use a code" in the store menu) and enter the 25 characters with the on-screen keyboard.
Open the Microsoft Store app, select your profile picture → Redeem code or gift cards, enter the code and follow the prompts.
Xbox and Microsoft gift cards are issued for one country or currency. A US card redeems on Microsoft accounts set to the United States, a euro card on accounts in a euro country. Your account region is shown at account.microsoft.com under Your info. Check it before you buy — changing it later is limited and the balance does not follow.
Choose the version for your Microsoft account's country; the balance is credited in that currency.
The card and your Microsoft account are set to different countries. Redeem it on an account from the card's country.
Check your order history at account.microsoft.com — the balance may already be on this account, or on another Microsoft account you use.
A character was misread. Paste the code straight from the email instead of retyping it, then try once more.
Yes, in practice: both add money to your Microsoft account balance, which works in the Xbox store and the Microsoft Store on Windows.
Yes. Microsoft account balance can pay for Game Pass, games, add-ons, in-game currencies and apps sold in the Microsoft stores.
Microsoft account balance does not expire under Microsoft's standard terms; it stays until you spend it.
Yes. GiftKong sells Xbox cards for the regions listed above, plus Microsoft and Game Pass codes, paid with Bitcoin, Ethereum, Monero, USDT and four other options. The code is emailed as soon as the payment confirms.
At account.microsoft.com → Payment options, or on Xbox in Settings → Account → Payment & billing.
Xbox, Microsoft and Game Pass codes, paid with crypto and emailed as soon as the payment confirms.
A real person reads every ticket and replies to the email on your order.
