DataMockSeed

IBAN validator: verify the check digits (mod 97)

To validate an IBAN, move the first 4 characters to the end, replace each letter with a number (A=10 … Z=35) and divide the result by 97: the IBAN is valid if the remainder is 1. This IBAN validator also checks the length for each country and the national account check digits, such as those of the Spanish CCC.

Paste an IBAN and we check the mod 97 calculation defined by the ISO 13616 standard, and show the bank and BIC if we recognize them.

Quick validator

Check whether a DNI, NIE, CIF, IBAN, card number, NSS or CCC has a valid format and check digit.

The validator checks format and check digits. It does not check whether the document or account exists. The value is never sent to any server or stored in the URL.

How it's calculated

Spanish CCC (bank + branch + check digits + account) with IBAN check digits.

Generated sample
ES9314653022409350215733

The country code and '00' move to the end, letters become numbers and mod 97 is computed.

  1. 1
    BBAN + country + '00'
    14653022409350215733ES00
  2. 2
    Letters → numbers (A=10 … Z=35)
    14653022409350215733142800
  3. 3
    Mod 97 remainder
    5
  4. 4
    Check digits = 98 − remainder
    93

Frequently asked questions

Which countries does the IBAN validator support?

Spain, Germany, France and Portugal. An IBAN from any other country is flagged as unsupported, even if its check digits are correct.

How do I know which bank an IBAN belongs to?

If the IBAN's bank code is in the DataMockSeed catalog, the validator shows the bank name and its BIC next to the result.

Does the validator check that the account exists or has funds?

No. It only checks the IBAN's format and check digits; it does not access any banking system.

Keep exploring

Generate test IBAN numbersFull validatorBrowse the full catalog

Need to validate another data type? Use the full validator.