My gold and gamepass ultimate ran out yesterday so i purchased a 12 month prepaid card

Since your Ultimate subscription had run out before you added the card, you would just get the 12 months of Gold from the card. It wouldn't convert to Ultimate unless you purchase an Ultimate subscription after adding the card or you had Ultimate when
you added the card.

Hmm, I have done this before with a smaller gift card. It should just give you the Game pass. as for me it gave it to me after putting in the code. I hope this helps. Be sure to contact Xbox Support if you can't find any answer

https://support.xbox.com/en-US/ (XBox Support link)

(1-800-642-7676) *Customer support number)

*edit* the post above this one I think is the answer*

There's not a 12 month subscription for Ultimate. You can buy a 12 month prepaid card for Gold and then purchase 1 month of Ultimate (after adding the Gold) to convert it to Ultimate.

so you're saying if I purchase a Xbox Live gold membership prepaid card for 12 months while Xbox Live Gold Pass ultimate is enabled it'll convert those 12 months into Xbox Live Gold pass ultimate

If you add a prepaid Gold or standard Game Pass prepaid card while you have an active Ultimate subscription, it will convert to Ultimate at a ratio that is based on price rather than time. 12 months of Gold is equal to 4 months of Ultimate. In order to get the full 12 months of just Gold, you have to cancel Ultimate or wait for it to completely run out before you added the card.