Your Apple ID is the account you use to access Apple services. To make purchases in the iTunes Store, Apple Books Store, App Store, third-party apps, and more, you need to provide a payment method and keep it on file in your account. Apple will use this payment method any time you want to make a purchase. You can also use it to quickly set up Apple Pay, so you can purchase physical goods and services in apps, retail stores, and websites.
In certain cases, Apple might also use your payment information to help verify your identity. You might need to verify your payment information to reset your Apple ID password, set up Family Sharing, create a child account, or to start making purchases from a new device.
When you set up your payment method
When you set up a payment method, make sure that all of your account information—like your name, billing address, and phone number—matches the credit card information on file with your financial institution. After you add your information, Apple places a temporary authorization hold on the payment method to confirm that it's valid. If you're using a credit card, it must be active and not expired.
When you need to verify your identity
You can use your payment method to verify your identify with Apple, or to do things like set up Family Sharing or create a child account. It can also help to verify your identity, and shorten recovery time, if you're trying to regain access to your Apple ID.
Make sure that you enter the same card information that you use to make purchases with the iTunes Store, Apple Books Store, App Store, and iCloud. Apple might place a temporary authorization hold on your payment method to confirm your information.
About the temporary authorization
Authorization holds might appear as charges, but are removed by your card issuer after a short time, which varies by financial institution. If you set up a new card, change payment information, or make a purchase, Apple might place a temporary authorization on your card, or ask to verify your card details. If you have questions about the way your card handles authorization requests, contact your financial institution.
If your authorization attempt fails
If you enter the correct payment details but you're asked to reenter the correct security information, contact your card issuer. Your financial institution might be declining your authorization attempts.