IBAN-VALIDATION

The MOD 97 computation verifying an IBAN without calling the bank.

Definition

Algorithm: (1) move the first 4 characters (country code + check digits) to the end, (2) replace each letter with its alphabetical position + 9 (A=10, B=11... Z=35), (3) compute modulo 97. The result must be 1. ISO 7064 standardised method. Does not eliminate all invalid IBANs (a closed account number may still pass the checksum) but filters 100 % of typing errors.

Origin

Method defined by ISO 13616-1 (IBAN structure) and ISO 7064 (MOD 97-10 checksum).

Example in context

FR1420041010050500013M02606 → rearranged → 14200410100505000130122606 + check 14 → verify modulo 97.

Related terms

• IBAN — validated identifier.