To refund to a bank account, it is necessary for you to provide a refund recipient for refund purposes. This refund recipient has to be a bank account owned by the sender.
If you have not created a Refund Recipient for your user’s source bank account, you will have to create it here. The source bank account is the bank account from which the money is deducted to fund the transfer.
A Refund Recipient is similar to a normal recipient, but is used to specify where the money should be refunded to during cases where there are bounce backs or if we are unable to send to the intended recipient.
This can be done with the Create a Refund Recipient API.