Paypal do it. When you hook up an account they send 5p or something, and require the transaction code number for validating the account. Seems like if the bank

Paypal do it. When you hook up an account they send 5p or something, and require the transaction code number for validating the account. Seems like if the banks cared they could add a very similar process for adding personal transfers, and mostly automate it for their customers. Except it's customer money being lost so the impetus is not there.