Updating billing info on itunes
You'll see a box with the heading "Payment Information" under Account Information, click the Edit button there.
You will then see a form for entering your payment information, add your new card details on the right and click save.
Here’s how to change your i Tunes credit card on your i Phone and on your computer.
If you are the site owner (or you manage this site), please whitelist your IP or you think this block is an error please open a support ticket and make sure to include the block details (displayed in the box below), so we can assist you in troubleshooting the issue.The card you enter here will be used on the Apple Online Store, i Tunes and Apple App Store.Each Apple ID can be assigned a credit card for use with i Tunes, the App Store, i Books, and any other purchases you make via apps on i Phone.If you move, change credit cards, or make some other change that affects this information, you need to update your i Tunes account so that it continues to work.The process you use to do this depends on what you need to edit and whether you use a computer or a mobile device.