Sign in to your Apple ID account page and edit / update your Apple ID details -> https://appleid.apple.com
- On the Sidebar click Payment methods -> then tap Payments Methods and tap Manage payment method.
Or -> Add a payment method to your Apple ID
Add a payment method to your Apple ID – Apple Support (UK)
- If you want to change your card, you need to add first the new card, then remove the old card.
See also -> Payment methods you can use with your Apple ID
Payment methods you can use with your Apple ID – Apple Support (UK)
fyi: Not all credit & debit cards seem to work with App Store / iTunes Store, try a different one, or preferably a credit card. If your card is not accepted as a paymenf method, you need to contact your bank.
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If your payment method is declined in the App Store or iTunes Store, see ->
If your payment method is declined in the App Store or iTunes Store - Apple Support
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How to complete your purchase if a payment failed or was declined
- On your iPhone or iPad, open the Settings app.
- Tap your name.
- Tap Payment & Shipping.
- Add a different payment method and remove the old one.
- Try to complete your purchase.
If you still can't make a purchase
If you have followed all the steps and instructions and if you still need help, get more help and assistant from Apple directly, see Contact Apple for support and service -> Contact Apple for support and service – Apple Support (UK)