Adding months to Xbox Live with a prepaid card. Possible?

Question

Last december I bought a 12 month subscription with my 360 to Xbox Live. I still have a few months left to go. If I buy a 13 months prepaid card and I enter the code now, will it add 13 months from when my subscription expires, or will i only have 13 months from when I enter the code?

Should I wait until my current subscription runs out before entering the code?

Answer 1

yes it will add more months to it   so go ahead and add a card now