How to validate an IBAN
Enter one candidate or a list of candidates. The result shows Valid IBAN or Invalid IBAN, then lists the country, length, BBAN structure, and MOD-97 checksum checks. Spaces are removed and letters are changed to uppercase before the checks run, with a reason shown for each failed check.
How to check one IBAN
- Open Single Candidate and enter a value in IBAN candidate.
- Review the status, reasons, and validation details.
The result lists Formatted IBAN, Length, Allowed characters (letters/digits only), Country code, Country, Check digits, BBAN, Length matches country, Structure matches country, and MOD-97 checksum. A recognized German candidate looks like this:
DE89 3704 0044 0532 0130 00
Formatted IBAN: DE89 3704 0044 0532 0130 00
Status: Valid IBAN
Country: Germany
MOD-97 checksum: PassesCharacters outside letters and digits fail the allowed-characters check after spaces are removed. An empty field produces no result panel.
How bulk IBAN validation handles lists
- Open Bulk Candidates and paste values into IBAN candidates, one per line, separated by commas, or mixed.
- Review the status and reasons for each row in Validation results.
- Choose Copy CSV or Download CSV when you need the result list outside the page.
Bulk input splits lines at commas, trims each item, and ignores empty items. The CSV columns are IBAN, Country, Length, Structure OK, Checksum OK, Status, and Reasons. Download CSV uses iban-validation-results.csv. Upload accepts .txt and .csv files.
GB29 NWBK 6016 1331 9268 19, XX00INVALID
IBAN, Country, Length, Structure OK, Checksum OK, Status, Reasons
GB29 NWBK 6016 1331 9268 19, United Kingdom, 22, Yes, Yes, Valid,
XX00 INVA LID, Unknown, 10, N/A, No, Invalid, ""XX" is not a recognized IBAN country prefix; Fails the MOD-97 checksum (ISO 7064)"An empty bulk submission creates no result rows, so Copy CSV and Download CSV stay unavailable.
What an IBAN format checker verifies
- Checks that the normalized value contains letters and digits only.
- Reads the two-letter country prefix and requires two check digits.
- Compares total length with the recognized country's expected length.
- Compares the BBAN portion with that country's digit and letter pattern.
- Checks the MOD-97 checksum when the country and check digits allow it.
The recognized country codes come from the validator's local country list. With an unknown prefix, country-specific length and structure checks are unavailable. A checksum reason can still appear when the check-digit position contains two digits.
What a valid IBAN result does not confirm
A Valid IBAN result means the candidate passed the implemented character, country, length, BBAN structure, and MOD-97 checks. It does not verify that an account exists, is open, belongs to a person, can receive a transfer, or is accepted by a bank. The validator does not perform a bank lookup or identify an account holder.
Where IBAN validation comes up
A finance clerk can check a pasted list before importing payment details into another system, then copy the CSV rows with their reasons.
A developer can test country-specific examples such as the German value above and inspect the exact length, BBAN, and checksum fields when a candidate fails.
A support agent can check the format of one customer-supplied value, then explain an invalid result using the displayed reason without treating it as an account lookup.
IBAN Validator and related checks
Use Data Validation Tools to choose another validator. Credit Card Validator checks card numbers with Luhn checks. Email Validator checks email syntax, domains, quoting, length, and character rules. VAT Number Validator checks VAT prefixes, lengths, and checksums.
Frequently asked questions
Does a valid IBAN result mean the account exists?
No. It confirms the candidate passed the implemented format, country, length, BBAN structure, and MOD-97 checksum checks, but it does not confirm an account or transfer destination.
Does IBAN Validator send candidate values to a server?
The validator script processes candidate values in the browser and does not make a network request containing them. The page also loads other networked assets, so apply your organization's data-handling policy to real account numbers.
Which IBAN country prefixes does it recognize?
It recognizes the country codes in the validator's local country list. An unknown prefix is flagged, and country-specific length and BBAN structure checks are unavailable.
Can I check multiple IBANs at once?
Yes. Bulk Candidates accepts one candidate per line, comma-separated values, or a mixture of both, then shows one status and reason set per row.