If you've ever presented a paper check to make payment for something, or if somebody ever paid you with a check, you may have wondered what all the numbers across the bottom referred to. While you may really only be interested in the amount in the payment box, it's worth understanding more about the other numbers, too.
History. Bank routing numbers are assigned to eligible American financial institutions by the American Bankers Association (ABA). Only state and federal chartered financial institutions that are able to hold an account at the Federal Reserve Bank are assigned ABA routing numbers. According to the ABA, the system was implemented in 1910 and is intended to enable all transactions to be identifiable to the institution responsible for the payment. Although originally intended solely for check payments, the system has since been expanded to include electronic fund transfers and online banking transfers.
Format and other names. The ABA routing number is a nine-digit indicator. It is sometimes referred to as the "check routing number," the "ABA number" or the "routing transit number RTN." The routing number will vary according to where the account was opened and the type of transaction being made.
Different types. There may be a different bank routing number for paper check payments, for electronic (direct deposit/automatic) payments or for wire transfers. The number will vary according to the bank through which the payment is to be made and the state in which the account was opened. If you are ever unsure which bank routing number to use, you should contact your branch or personal banker for advice.
Finding the number on checks. As outlined by Bank of America, the ABA bank routing number can be found at the bottom of your check. It is normally the first, nine-digit number to be printed on the foot of the check. The next number will be your account number, after which you will find the check number.