3 ms·

This is elementary school level math, no citation needed. The modulo 97 checksum offers known guarantees.

• ciupicri 5y ago
  I think there's a misunderstanding here. If the customer mistypes the IBAN account number, the bank (website, app etc) will automatically reject it as invalid immediately, he won't have to deal with the customer service.
  • rosndo 5y ago
    Yes, but the misunderstanding is on your side. This is overly simplified so not entirely accurate, but if 100 customers typo their destination IBAN the modulo 97 checksum will probably let 3 of them through.
    • ciupicri 5y ago
      Wikipedia says that "where used, IBANs have reduced trans-national money transfer errors to under 0.1% of total payments", although there's no source for the claim.
      • rosndo 5y ago
        0.1% of total payments, i.e 1 in 1000 payments. That’s not 0.1% of typos but all payments.