I redeemed an iTunes card but i am still prompted for billing info when trying to purchase music. Why is my iTunes card not being redeemed in this case?

Hello Shannel23,

Thanks for using Apple Support Communities.

If this is your first time using the iTunes Store with the Apple ID, then a payment source is required to be added to your account. Once you add the payment type, you can then change the payment type to none, leaving just your gift card.

If you're using the store for the first time with an existing Apple ID, you must provide a payment method. After you create the account, you can change your payment information to None.

If you're creating a new Apple ID, you might be able to create an account without entering your credit card details.

Why can’t I select None when I edit my Apple ID payment information? - Apple Support

The way iTunes Store bills sales is that if you have a balance in the iTunes Store, such as a gift card, that source is debited first. After that depletes, your payment information on file is used for payments.

How iTunes Store purchases are billed - Apple Support

Have a good one,

Alex H.

Take care,

Alex H.