When you want to conduct an international transaction, your bank will run the IBAN characters through the payment system.
The bank is able to confirm the receiver and sender's accounts in this way. The bank proceeds to process the payment if the accounts are legitimate.
The transaction will fail if an IBAN is supplied improperly and there is no account associated with that IBAN. The transfer will go through if a corresponding account exists, and the transaction can only be revoked with the recipient's approval.
On the other hand, most banks utilize an IBAN checker, also called an IBAN lookup, to ensure that genuine IBANs are error-free.