If you are entering your bank details for the direct debit request, the system checks for valid sort codes and account numbers. Please double check that you are entering the correct account number and sort code. If this is not accepted, it would appear that your details do not match and we are unable to proceed with your request for payment by instalments. If you have already completed your direct debit mandate and the screen is asking for a card number, please check it is the card you declared to pay your deposit. If the problem remains, please call Customer Service on 0330 022 0200.