Routing errors were therefore frequent causing payments to be delayed and incurred extra costs to the sending and receiving banks and often to intermediate routing banks also.
The underlying rules for IBANs is that the account-servicing financial institution should issue an IBAN, as there are a number of areas where different IBANs could be generated from the same account and branch numbers that would satisfy the generic IBAN validation rules. Routing errors were therefore frequent causing payments to be delayed and incurred extra costs to the sending and receiving banks and often to intermediate routing banks also.
In particular, the computer program that accepts an IBAN will be able to validate:
Is the country code valid?