If money is being transferred across international borders, an international network is used. The checksum enables the initiator of any transaction to perform a sanity check of any specified bank account number on their own computer prior to actually initiating a request. Those countries which use International Bank Account Numbers (IBAN) have mostly integrated the bank code into the prefix of specifying IBAN account numbers.
If money is being transferred across international borders, an international network is used. Many European countries use the IBAN as a means of identifying bank account numbers, but transfers to, amongst others, the United States and Australia make use of the BIC Codes.