A financial institution number is a unique identifier assigned to each specific bank or financial institution. This number, used during interbank transactions, is sometimes a piece of the routing transit number to identify the institution, branch location, and customer account. Most FINs are three digits in length; however, the placement within the routing number varies between countries.
In Canada, the FIN is reported in the routing number after the check number and branch identification number. It is used to simplify and expedite transaction processing. In communicating this information to another bank, the appropriate banking transaction entry is easier to complete with higher accuracy.