Check an IBAN Number
Enter an IBAN to validate its format, country, and MOD-97 checksum. All processing happens in your browser — your data never leaves your device.
Batch Validate IBANs
Paste multiple IBANs, one per line. All validation happens in your browser.
| # | IBAN | Status | Country | Details |
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IBAN Country Reference
Searchable list of all supported IBAN countries with their format, length, and an example.
| Country | Code | Length | Format | Example |
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How IBAN Validation Works
An IBAN (International Bank Account Number) is validated through a four-step process defined by ISO 13616 and ISO 7064:
- Country Code Check — The first two characters must be a valid ISO 3166-1 alpha-2 country code.
- Length Check — Each country has a fixed IBAN length. For example, German IBANs are always 22 characters, UK IBANs are 22, and French IBANs are 27.
- Character Validation — All characters must be alphanumeric (A-Z, 0-9). Spaces and dashes are removed before validation.
- MOD-97 Checksum — The check digits (positions 3-4) are verified using the ISO 7064 MOD-97-10 algorithm. The IBAN is rearranged and converted to digits, then divided by 97. The remainder must be 1.
This tool performs all four checks entirely in your browser. Your IBAN is never transmitted, stored, or logged.
Why AI Cannot Replace This Tool
Large language models frequently hallucinate IBAN validation results. They may claim an IBAN is valid when the MOD-97 checksum fails, or reject a correctly formed IBAN due to misinterpretation of country-specific length rules. AI models have no ability to perform arithmetic modulo operations reliably — they predict text patterns rather than computing exact checksums. This tool uses deterministic JavaScript arithmetic to compute the exact MOD-97 remainder, with no approximation, no hallucination, and no variability. Every validation is bit-exact, reproducible, and mathematically guaranteed.
- AI cannot perform MOD-97 arithmetic modulo operations
- AI confuses country-specific IBAN length rules
- AI hallucinates check digit validation (often says invalid IBANs are valid)
- Your financial data stays private — never transmitted to any server
- Deterministic validation — same IBAN always produces the same result
- Batch validation impossible for AI without making multiple API calls
Frequently Asked Questions
What is an IBAN?
IBAN stands for International Bank Account Number. It is an internationally agreed standard (ISO 13616) for identifying bank accounts across national borders. An IBAN consists of up to 34 alphanumeric characters: a two-letter country code, two check digits, and a Basic Bank Account Number (BBAN) that includes the bank code and account number. IBANs reduce errors in international payments by providing a single, standardized account identifier.
What does MOD-97 mean?
MOD-97 is the checksum algorithm defined in ISO 7064 that verifies an IBAN's check digits. The process: (1) move the first four characters (country code and check digits) to the end of the IBAN, (2) convert all letters to numbers (A=10, B=11, ..., Z=35), (3) compute the remainder when dividing by 97. If the remainder is 1, the check digits are correct. This is the same algorithm banks use to catch typing errors before processing international payments.
Does a valid IBAN mean the account exists?
No. IBAN validation only confirms that the number is correctly formatted and the check digits are mathematically valid. It does not verify that the bank account actually exists, is open, or belongs to the intended recipient. Only the issuing bank can confirm an account's existence. Think of IBAN validation as a "well-formedness" check — it catches typos and format errors, but it doesn't guarantee the account is active.
Which countries use IBAN?
IBAN is primarily used in Europe, including all EU and EEA member states, the United Kingdom, Switzerland, and many neighboring countries. It is also used in parts of the Middle East (Saudi Arabia, UAE, Qatar, Israel, Turkey), North Africa (Tunisia, Morocco), the Caribbean, and Latin America (Brazil). The United States, Canada, Australia, New Zealand, China, and Japan do not use IBAN and instead rely on routing numbers, sort codes, or other national systems.
Can I use this tool to validate real IBANs?
Yes. This tool is safe for real IBANs because all validation happens in your browser — no data is ever sent to any server. You can verify by opening your browser's Developer Tools (F12), going to the Network tab, and confirming that no network requests are made when you click Validate. Your financial data stays completely private on your own device.
What is the difference between IBAN and SWIFT/BIC?
An IBAN identifies a specific bank account, while a SWIFT/BIC code identifies a specific bank or financial institution. Think of IBAN as your account number and SWIFT as the bank's address. For international transfers, you typically need both: the recipient's IBAN for the account and the bank's SWIFT/BIC code to route the payment to the correct institution.
What happens if I enter an invalid IBAN?
This tool will tell you exactly why the IBAN is invalid. Common reasons include: wrong country code, incorrect length for the specified country, invalid characters (such as spaces or special characters — though these are automatically removed before validation), or failed MOD-97 checksum (indicating the check digits are incorrect). Each error is displayed with a clear explanation so you can fix the number.
Can I validate multiple IBANs at once?
Yes. Switch to the Batch Validate tab and paste multiple IBANs, one per line. Click "Validate All" to check every IBAN simultaneously. Results are displayed in a table showing each IBAN's status (Valid/Invalid), detected country, and any error messages. You can copy the results for your records.
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