I had this issue when trying to add my bank details. In my case I was in the UK and gave my sort code, account number and IBAN, and got the error "The IBAN number does not match the account number". It seems like the IBAN my banking app showed was not the same account as the sort code and account number. Maybe they have two accounts and somehow reconcile them on the backend? Idk The fix: used the site recommended in another forum thread (https://developer.apple.com/forums/thread/756362?answerId=832919022#832919022) to calculate the correct IBAN given the sort code and account number: https://www.ibancalculator.com/bic_und_iban.html If you select United Kingdom, it will ask for sort code and account number, and then give you an IBAN. When I gave Apple this IBAN, it worked.