IBAN Validator

Paste an IBAN, see whether the country code, length, BBAN shape, and mod-97 check digits all line up. Validate one or many at once. Live, in your browser, no upload.

Try:
one IBAN per line · up to 200
0 valid 0 invalid

How IBAN validation works
  • An IBAN is composed of a 2-letter country code, 2 check digits, and a country-specific BBAN (Basic Bank Account Number).
  • The validator runs three checks: the country is one we know, the total length matches that country's expected length, and the BBAN portion matches that country's documented character pattern.
  • If those pass, it runs the mod-97-10 check (ISO 7064): the IBAN is rearranged so the country+check move to the end, letters are converted to numbers (A=10…Z=35), and the result must leave remainder 1 when divided by 97.
  • All arithmetic uses BigInt internally — the longest IBANs are 31 characters and rearrange into a 60+ digit number, which JS numbers can't represent exactly.
  • Spaces, dashes, dots, and lowercase letters are stripped before validation. You can paste DE89-3704-0044-0532-0130-00 or de89 3704 0044 0532 0130 00 — same result.
  • This validator confirms structural correctness only. It does not verify that the IBAN corresponds to a real, active bank account.
  • Nothing is uploaded. The whole thing runs in your browser.