In the United States, an ABA routing transit number (ABA RTN) is a nine-digit code printed on the bottom of checks to identify the financial institution on which it was drawn. The American Bankers Association (ABA) developed the system in 1910 to facilitate the sorting, bundling, and delivering of paper checks to the drawer's (check writer's) bank for debit to the drawer's account.
Newer electronic payment methods continue to rely on ABA RTNs to identify the paying bank or other financial institution. The Federal Reserve Bank uses ABA RTNs in processing Fedwire funds transfers. The ACH Network also uses ABA RTNs in processing direct deposits, bill payments, and other automated money transfers.
Management
Since 1911, the American Bankers Association has partnered with a series of registrars, currently Accuity, to manage the ABA routing number system. Accuity is the Official Routing Number Registrar and is responsible for assigning ABA RTNs and managing the ABA RTN system. Accuity publishes the American Bankers Association Key to Routing Numbers semi-annually. The "Key Book" contains the listing of all ABA RTNs that have been assigned.
There are approximately 26,895 active ABA RTNs currently in use. Every financial institution in the United States has at least one. The Routing Number Policy allows for up to five ABA RTNs to be assigned to a financial institution. Many institutions have more than five ABA RTNs as a result of mergers.
ABA RTNs are only for use in payment transactions within the United States. They are used on paper check, wire transfers, and ACH transactions. On a paper check, the ABA RTN is usually the middle set of nine numbers printed at the bottom of the check. Domestic transfers that use the ABA RTN will usually be returned to the paying bank. The same bank may use different routing numbers for checks vs. wire transfers.
Incoming international wire transfers also use a BIC code, also known as a SWIFT code, as they are administered by the Society for Worldwide Interbank Financial Telecommunication (SWIFT) and defined by ISO 9362. In addition, many international financial institutions use an IBAN code.
The IBAN was originally developed to facilitate payments within the European Union but the format is flexible enough to be applied globally. It consists of an ISO 3166-1 alpha-2 country code, followed by two check digits that are calculated using a mod-97 technique, and Basic Bank Account Number (BBAN) with up to thirty alphanumeric characters. The BBAN includes the domestic bank account number and potentially routing information. The national banking communities decide individually on a fixed length for all BBAN in their country.
History
thumb|right|250px|In 1911 the new Burroughs Transit Machine, made by the [[Burroughs Corporation|Burroughs Adding Machine Company, was advertised in the first edition of the bank directory Key to Numerical System of the American Bankers' Association.]]The bank numbers in the United States were originated by the American Bankers Association (ABA) in 1911. Banks had been disagreeing on identification. The ABA arranged a meeting of clearing house managers in Chicago in December 1910. The gathering chose a committee to assign each bank in the country convenient numbers to use. In May 1911, the American Bankers Association released the codes. The numerical committee was W. G. Schroeder, C. R. McKay, and J. A. Walker. The publisher of the new directory was Rand-McNally and Company. The ABA clearing house codes are like the sub-headings in a decimal outline. The prefixes mean locations and the suffixes banking firms within those locations. Half of the prefixes represent major cities the other half represent regions of the United States. Lower prefixes are used for higher populations, first based on the 1910 U. S. Census. Likewise, within each prefix area banks are numbered in order of city population and bank seniority, although single-bank towns are numbered in alphabetical order. When a new bank is being organized, the current publisher of the directory of banks assigns it a transit code. The American Bankers Association asked banks to use the directory exclusively so banks would agree on how to sort checks. The book was abbreviated Key to Numerical System of The American Bankers Association, and as the Key. It was published by Rand McNally & Co. In 1952 Rand McNally moved its corporate headquarters to Skokie, Illinois, and became more interested in publishing maps. Also in Skokie is a company called Accuity, which from its history has been the official registrar of ABA bank numbers since 1911. By 2014 it was the publisher of the semi-annual ABA Key to Routing Numbers and was owned by Reed Business Information, British publisher of reference works for professionals, which in turn is owned by Reed-Elsevier, English-Dutch publisher of online format reference works for professionals. Over the years the ABA's identification numbers for banks accommodated the Federal Reserve Act, the Expedited Funds Act and the Check 21 Act. By 2014 the Key included the U. S. Federal Reserve's nine-digit magnetic-ink routing numbers.
Formats
300px|thumb|right|A check showing the fraction form (top middle-right, 11-3167/1210 plus branch number 01) and MICR form (bottom left, 129131673) of the transit number.
The ABA RTN appears in two forms on a standard check – the fraction form and the MICR (magnetic ink character recognition) form.
The first two digits of the nine digit RTN must be in the ranges 00 through 12, 21 through 32, 61 through 72, or 80.
The digits are assigned as follows:
- 00 is used by the United States Government
- 01 through 12 are the "normal" routing numbers, and correspond to the 12 Federal Reserve Banks. For example, 0260-0959-3 is the routing number for Bank of America incoming wires in New York, with the initial "02" indicating the Federal Reserve Bank of New York.
- 21 through 32 were assigned only to thrift institutions (e.g. credit unions and savings banks) through 1985, but are no longer assigned (thrifts are assigned normal 01–12 numbers). Currently they are still used by the thrift institutions, or their successors, and correspond to the normal routing number, plus 20. (For example, 2260-7352-3 is the routing number for Grand Adirondack Federal Credit Union in New York, with the initial "22" corresponding to "02" (New York Fed) plus "20" (thrift).)
- 61 through 72 are special purpose routing numbers designated for use by non-bank payment processors and clearinghouses and are termed Electronic Transaction Identifiers (ETIs), and correspond to the normal routing number, plus 60.
- 80 is used for traveler's checks
The first two digits correspond to the 12 Federal Reserve Banks as follows:
{| class="wikitable"
! Primary<br />(01–12)
! Thrift<br/>(+20)
! Electronic<br/>(+60)
! Federal Reserve Bank
|-
|01 || 21 || 61 || Boston
|-
|02 || 22 || 62 || New York
|-
|03 || 23 || 63 || Philadelphia
|-
|04 || 24 || 64 || Cleveland
|-
|05 || 25 || 65 || Richmond
|-
|06 || 26 || 66 || Atlanta
|-
|07 || 27 || 67 || Chicago
|-
|08 || 28 || 68 || St. Louis
|-
|09 || 29 || 69 || Minneapolis
|-
|10 || 30 || 70 || Kansas City
|-
|11 || 31 || 71 || Dallas
|-
|12 || 32 || 72 || San Francisco
|}
The third digit corresponds to the Federal Reserve check processing center originally assigned to the bank.