Routing number format
The routing number consists of 9 digits:
The ABA Routing Number is of the form XXXXYYYYC
- XXXX is Federal Reserve Routing Symbol
- YYYY is ABA Institution Identifier
- C is the Check Digit
Federal Reserve Routing Number
The Federal Reserve Routing Numbers were originally assigned in the systematic way outlined below, reflecting a bank's geographical location and internal handling by the Federal Reserve. However, the link is today tenuous - following banking consolidation, many banks use a routing number from a now-defunct bank, while the Federal Reserve no longer assigns specific numbers for thrifts, nor does the "check processing facility" have any current meaning, as check processing is now centralized within each Federal Reserve district.
First two digits
The first two digits of the nine digit ABA number 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"
- 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 cheques
The first two digits correspond to the 12 Federal
Reserve Banks as follows:
|Federal Reserve Bank
Third and fourth digits
The third digit corresponds to the Federal Reserve check
processing center originally assigned to the bank, while
the fourth digit is "0" if the bank is located in the Federal
Reserve city proper, and otherwise is 1-9, according to which state
in the Federal Reserve district it is.
The check digit provides a checksum test using a position-weighted sum of each of the digits. High-speed
check-sorting equipment will typically verify the checksum, and
route the item to a reject pocket for manual examination, repair,
and re-sorting. Mis-routings to an incorrect bank are thus greatly
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