Bank number

A bank number is a bank code used to identify a bank for electronic purposes in the United States. Bank numbers such as Bank Identifier Code (BIC), Bank Identification Number (BIN), and Routing transit number (RTN) categorizes a bank for machine-aided sorting of checks and so forth. The term is used in some deposit-slip instructions such as "List checks separately by bank number."

In the U.S.A. the first part stands for an area and the second part for a bank in that area. In the first half of the 20th century the area was either a major city or one of the 50 United States of America. After about 1950 the area was a central bank location. The old numbers were like 3-1, the new numbers were like 0310-0001 with hyphen now only implied. A ninth check digit was added to the end of the newer bank numbers. Since the 1950s a transitional form like 3-1/310 has also been printed on checks.

Some sample deposit slips say "List checks singly" with checks listed only by their amounts.

The bank number is in the clearing-bank code at the bottom edge of the check. The code contains the check routing and funds availability and transit number and bank identifier. The first two numbers tell the reserve bank, the second two tell its branch and check-clearing information, the next four is the paying bank's number, and the ninth digit is for error control. The numbers at the bottom edge of the check were invented in the 1950s and automated the check payment process. The clearing-bank code is also called the routing/transit number and is similar to the fractional routing/transit number also on the check. In the fraction, the institution identifier is part of the numerator. The check's bank is after the first hyphen in the numerator and its federal bank is in the denominator. Often people write "bank over fed bank" on a deposit ticket next to the amount of the check. Others have used "city hyphen bank," five to six digits, found in the numerator to list checks by bank on deposit slips and it has been used in other ways as well. The institution identifier is 1 or above and is located in the numerical and fractional routing numbers on the check. The non-fractional code is in between transit characters - such as ⑆ - near the lower edge of the check. The second group of four digits in that number, which precede any parity-check digit, is the bank's number. The other code, the fractional routing symbol, was on American checks before the use of MICR machines began in the 1950s. The fractional symbol is in the format, XX-XX/XXXX. From that fraction the nine-digit routing number was determined. The part of the fraction before the hyphen is not used in the 9-digit routing number. The fraction's denominator, however, is and denotes in what branch of the federal reserve the bank saves its money.

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