An IBAN comprises data that can be used to authenticate your account number, your bank's country of origin, and other account information.
The code is compared to the IBAN information when you make a payment to guarantee that the receiver is valid.
The transaction will fail if an IBAN is entered improperly and no account is associated with it. The bank will transfer the funds if a comparable account exists, and the funds can only be reversed with the recipient's agreement.
With an IBAN checker the bank can ensure that legal IBANs are error-free.