Payment
Why can’t I remove old credit card and add new one
iPhone 11, iOS 14
Question marked as
Top-ranking reply
Try updating to the latest version of iOS (Currently iOS 14.6)
Also if you have any active subscriptions and/or an unpaid balance, you can't remove all payment methods on your account.
You might want to try adding your new payment method first and then removing the old one.
Follow the steps at the link below:
Change, add or remove Apple ID payment methods – Apple Support