The American Banking Association offers an online search tool to consumers who need to verify an individual bank's ABA Routing Number. The search tool allows you to look up a financial institution by name, location or routing number. Companies that need to routinely verify ABA routing numbers should subscribe to the routing database registry at Accuity.com, according to the ABA.
The U.S. Federal Reserve has an E-Payments Routing Directory, posted on FRBServices.org, that provides routing numbers for financial institutions participating in federal reserve transactions with other institutions.
ABA Routing Numbers, also known as Routing Transit Numbers or ABA numbers, are nine-digit unique identifiers assigned to financial institutions that are responsible for payment of negotiable instruments such as checks. Only chartered financial institutions that are eligible to maintain an account at a Federal Reserve Bank can receive an ABA Routing number, according to the ABA. Institutions apply for a routing number through Accuity, the ABA's official registrar.
The bank routing number system was founded in 1910, and was originally developed in order to streamline the processing of paper checks. Over time, the ABA Routing system has evolved to incorporate Electronic Funds Transfer, debit cards, wire transfers, direct deposit, automated clearinghouse drafts and online banking, says the ABA.