ABA Routing Number Validator
Paste a 9-digit ABA routing number to check whether its check digit is correct.
Computed locally in your browser with the ABA 3-7-1 mod-10 check-digit scheme. Your routing number stays only on this page.
Validate a routing number check digit
Paste a 9-digit US bank ABA routing number to confirm its check digit, see the expected value, and read off the corrected number when the digit is wrong. The check uses the standard ABA weighted 3-7-1 mod-10 algorithm — distinct from the Luhn doubling scheme; spaces and hyphens are ignored. This is a checksum check only and does not look up the issuing bank or Federal Reserve district. Need to create valid fixtures instead? Try the routing number generator. For other identifiers, see the Luhn validator and the IBAN validator.