IBAN Validator
Validate an International Bank Account Number (IBAN) with the ISO 13616 mod-97 checksum and per-country length check. Runs entirely in your browser.
Batch check (one IBAN per line)
Validate an IBAN
Paste an International Bank Account Number to check its checksum and length. The tool shows the country, a grouped readable format, and the exact reason if it is invalid. Batch-check many at once or generate a valid example — all in your browser.
IBAN validation is defined by ISO 13616 with the mod-97-10 check from ISO/IEC 7064: move the first four characters (country code + 2 check digits) to the end, convert letters to numbers (A=10 … Z=35), and the whole number must leave remainder 1 when divided by 97. Each country also fixes an exact length and internal pattern (Germany 22, France 27, Spain 24, UK 22…), published in the SWIFT IBAN Registry. This tool applies both layers — country pattern and mod-97 — locally in your browser, and pinpoints what failed.
A valid IBAN structure does not guarantee the account exists, is open, or belongs to the person you expect: banks verify that during the actual transfer (and in the EU, via Verification of Payee). Use this to catch typos before payments, not as proof of ownership. Last verified: July 2026.
FAQ
How does the mod-97 check work exactly?
Rearrange: BBAN + country letters + check digits. Convert letters (A=10…Z=35), producing a long number; valid IBANs satisfy number mod 97 = 1. A single wrong character changes the remainder — the check catches ~99.9% of typos including most transpositions.
Why did my IBAN fail even though the digits look right?
The most common causes: wrong length for the country (each country is fixed), letter O typed instead of zero, or two swapped characters. The tool shows the expected length and the failing layer so you can fix the exact spot.
Does a valid IBAN mean the account is real?
No. Structure ≠ existence. Banks only confirm the account during processing; EU payment providers additionally match the beneficiary name (Verification of Payee) since 2025. Always double-check the beneficiary out-of-band for large transfers.
Are my IBANs uploaded for validation?
Never — the math runs entirely on your device, which is exactly why finance teams can safely batch-check supplier lists here. For bulk checks, paste one IBAN per line in batch mode and export the CSV verdicts.