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ABA Routing Numbers

The ABA Routing Number (a.k.a. ABA number or Routing Transit number) was developed by the American Bankers Association (ABA) in 1910. The ABA Routing Number serves to identify the specific financial institution responsible for the payment of a negotiable instrument.

Originally designed to identify only check processing endpoints, the ABA Routing Number has evolved to designate participants in automated clearinghouses, electronic funds transfer, and on-line banking. The ABA Routing Number has changed over the years to accommodate the Federal Reserve System, the advent of MICR, and the implementation of the Expedited Funds Availability Act (EFAA) and most recently, Check 21.

Who Is Eligible for an ABA Routing Number?

An ABA Routing Number will only be issued to a Federal or State chartered financial institution which is eligible to maintain an account at a Federal Reserve Bank.

Obtaining a Routing Number

The Official ABA Registrar of Routing Numbers, Accuity, is responsible for the assignment of routing numbers in accordance with the Routing Number Administrative Board Routing Number Policy. Accuity has served as the ABA's Official Registrar since 1911.

A newly organized financial institution must complete and submit an application to Accuity to be assigned its ABA Routing Number. For additional details regarding the application process, or to learn more about ABA Routing Numbers; transfer, reinstatement, retirement or ETI routing numbers contact:

Routing Number Registrar
1007 Church Street
Evanston, Illinois    60201
(800) 321-3373
(847) 933-8040 fax

ABA Key to Routing Numbers

In addition to its Registrar duties, Accuity publishes the American Bankers Association's Key to Routing Numbers. Since 1911, this Directory has been providing the industry with the official routing number information. The ABA Key to Routing Numbers is published semi-annually to keep pace with the rapid changes in the industry.

Inaccurate, incomplete, or missing routing number information can cost you thousands of dollars every month. With the latest ABA Key to Routing Numbers, you will always have the accurate data right at your fingertips. Each new edition covers thousands of updates, including title changes and newly assigned or retired routing numbers.

This invaluable resource can help you process checks and return items, initiate wire transfers, pre-authorize drafts, and handle collections. In addition to listings of every active nine-digit routing number (approximately 28,000), you also get five years of retired routing number information for research purposes.

Accuity offers a full line of payment solutions that includes routing numbers, in print, web-based look-up & electronic formats, to facilitate payment processing as well.  To order the ABA Key to Routing Numbers publication and other valuable banking products, contact:

P.O. Box 916
Skokie, Illinois 60076-0916
(800) 321-3373
(847) 933-8101 fax
Visit Accuity at:

For more information about Routing Numbers, please e-mail Jean McCord.


 Routing Number Lookup


​Need to find or validate an ABA Bank Routing Number? Visit our online lookup.

Where is the ABA routing number on my checks?