Some European banks may require the payer’s International Bank Account Number (IBAN) in order to safely create an Open Banking payment. For banks requiring an IBAN, you may want to prompt the user in advance so that they can be prepared. The user can find the IBAN on a bank statement or by logging into their online banking/app. If you can identify the payer, it is good practice to save the IBAN and pre-populate that information.