Warning! The full list of countries where the Live service is supported can be found HERE however the code cannot be activated in Romania and Cyprus.
Note! Xbox Live Card will extend your Gold subscription for 3 months. You may not be able to use this code if your subscription has 30 or less days left. We advise to wait until your subscription expires and then use the code.

How to activate 3 Months Xbox Live Gold Membership Card?
Visit this address: https://redeem.microsoft.com/
Sign in with your Microsoft account credentials
Enter the 25-character code and Confirm

You can find additional support for your Xbox Live account here: https://support.xbox.com/contact-us