IBAN Validator

How to use

1. 1Pick Single IBAN to check one number with a full breakdown, or Batch list to check one IBAN per line.
2. 2Paste the IBAN. Spaces, dashes, and lower case letters are normalized for you, so the standard print format works as is.
3. 3Read the verdict and the per-check details: country lookup, length, BBAN structure, mod-97 checksum, and (where published) bank and branch identifiers.
4. 4If the check digits are wrong, the panel shows what they should be for the rest of the IBAN, which is the same calculation used to generate IBANs from a domestic account number.
5. 5Use Copy formatted, Copy compact, or Copy masked for the single result, or Copy valid only in batch mode to keep the passing entries.

About this tool

IBAN Validator checks International Bank Account Numbers entirely in your browser using the algorithm published in ISO 13616 and the SWIFT IBAN Registry. Paste one IBAN to get a full breakdown, or switch to batch mode to validate a list one IBAN per line. The tool strips spaces and dashes, uppercases the input, splits off the country code (positions 1 and 2) and check digits (positions 3 and 4), and looks up the country in the registry. Each registered country defines a fixed total length and a fixed BBAN structure (digit, letter, or alphanumeric tokens with exact lengths), and both rules are enforced before the math runs. The checksum is the canonical mod-97 algorithm from ISO 7064: move the first four characters to the end, replace each letter with its number (A is 10, B is 11, through Z is 35), and take the resulting integer mod 97. A valid IBAN's remainder is exactly 1. The arithmetic uses BigInt so IBANs of every published length compute precisely without floating-point loss. Where the country publishes a structured BBAN, the result panel also extracts the bank identifier and the branch identifier (the UK sort code, the German BLZ, the French code banque and code guichet, the Italian ABI and CAB, the Spanish entidad and oficina, and the equivalents for around 80 other countries) so you can sanity-check that the IBAN belongs to the right institution. If the check digits are wrong, the tool also computes the correct check digits the IBAN should have for that BBAN, which is exactly the operation a payments engineer performs when generating an IBAN from a domestic account number. The single-IBAN view shows formatted output (in the standard 4-character groups), a compact form for code, a masked form (first four and last four characters revealed) for sharing in chat or tickets, and copy buttons for each. Batch mode validates entire lists at once, marks each row valid or invalid, summarizes counts at the top, and exposes a single click to copy the valid-only list back to the clipboard, which is useful for cleaning customer or vendor onboarding data. Useful for QA of payment forms, cleaning supplier and customer records, sanity-checking remittance details before transfers, debugging onboarding pipelines, and verifying that printed IBANs were typed correctly. Validation runs locally on your device, so any IBANs you paste here never leave your browser. A passing checksum proves the IBAN is well-formed; it does not prove the bank account exists or that the account holder is who you think they are. Always confirm with the recipient before sending a payment.

Free to use. Works in your browser. No signup, no login.