A routing number is an eight- or nine-digit American Bankers Association number that identifies the financial institution on which negotiable instruments such as checks and electronic debits are drawn. The routing number appears in two places on a check: on the magnetic ink character recognition strip at the bottom of the check and in fractional form at the top of the check. The fractional form of the routing number contains only eight digits and is used to manually process checks.
Begin the fractional routing number by writing the prefix, which indicates the region where the bank is located. The prefix should be at least 2 digits long. Valid prefixes include: 1 to 49: Federal Reserve cities or major banking centers 50 to 58: New York (50) & surrounding states (51-58) 59: Hawaii 60 to 69: Pennsylvania (60) & surrounding states (61-69) 70 to 79: Illinois (70) & surrounding states (71-79) 80 to 88: Missouri (80) & surrounding states (81-88) 89: Alaska 90 to 99: California (90) & surrounding states (91-99) 101: Various territories such as Guam and Puerto Rico
Write a dash "-" to the right of the prefix, followed by the three-digit ABA institution number. Each bank within a region has a unique three-digit identifier.
Write a forward slash "/" followed by the Federal Reserve routing symbol. The routing symbol depends upon where the check originated. For example, if your check came from the Philadelphia Federal Reserve district, you might write 031. The first two digits of the number indicate the Federal reserve district and the third digit is the reserve bank that serves the drawee institution. There are 12 Federal Reserve districts: 01-Boston 02-New York 03-Philadelphia 04-Cleveland 05-Richmond 06-Atlanta 07-Chicago 08-St. Louis 09-Minneapolis 10-Kansas City 11-Dallas 12-San Francisco
Contact the banking institution that issued a check to find out if the fractional routing number is valid. Modern checks have a magnetic ink character recognition code with a check digit to check the validity of a check: That check digit is not present in a fractional routing number.
The fourth digit in the Federal Reserve routing symbol was previously used to indicate credit availability but it has fallen into disuse. The number is required by the ABA to make up nine digits in a non-fractional transit routing number.
- Sapling: How to Determine Fractional Routing Numbers
- Today Accounting: Bank of America Fractional Routing Number
- G. W. A. Dummer, F. P. Thomson, J. Mackenzie Robertson. "Banking Automation: Data Processing Systems and Associated Equipment, Volume 1," Elsevier, 2014.
- Board of Governors of the Federal Reserve System. "Commercial Checks Collected through the Federal Reserve: Annual Data." Accessed Oct. 31, 2020.
- American Bankers Association. "ABA Routing Number." Accessed Oct. 31, 2020.
- Federal Reserve Banks. "Key to Routing Numbers." Accessed Oct. 31, 2020.
Stephanie Ellen teaches mathematics and statistics at the university and college level. She coauthored a statistics textbook published by Houghton-Mifflin. She has been writing professionally since 2008. Ellen holds a Bachelor of Science in health science from State University New York, a master's degree in math education from Jacksonville University and a Master of Arts in creative writing from National University.