Redeem an iTunes allowance, gift certificate, or Gift Card
If you received an iTunes Store allowance, gift certificate, iTunes Gift Card, or promotional code, you can use it to buy songs, videos, or audiobooks from the iTunes Store.
You need to set up an Apple ID for use with the iTunes Store before you can redeem anything in the iTunes Store. You don’t need to enter credit card information to redeem only the amount of a gift certificate or card.
Use an iTunes allowance, gift certificate, or iTunes Gift Card
If you aren’t already signed in to the iTunes Store, choose Store > Sign In, or click Sign In at the top of the iTunes Store window.
Below Quick Links, click Redeem, and follow the onscreen instructions.
The amount in your account appears to the left of your account name. When you click the Buy button to make purchases, the amount changes to show how much money remains in your account.
You can use a gift certificate only in the iTunes Store for the same country in which the certificate was purchased.