Hi Ross157,
Thanks for contacting Apple Support Communities!
We understand that you're attempting to add a debit card to Wallet and you're seeing an alert that the expiration date is incorrect but the date you're entering is correct.
Have you had this card added in Wallet before? If so, the card number and expiration date are connected via the Device Account Number and should automatically update. If it doesn't automatically update, you may need to remove the card and add it again as outlined here: Change or remove the payment cards that you use with Apple Pay
"Update your Apple Pay card number and expiration date
With Apple Pay, your payment card has a unique Device Account Number used to process payments and an expiration date associated with that Device Account Number.
If your card expires or you otherwise get a new card:
- The card number and expiration date linked to the Device Account Number should be updated automatically.
- If your card issuer doesn’t support these updates, you might need to remove the card and add it again."
We hope this helps you.
Cheers!