IBAN Validator
Validate any IBAN instantly. Checks country code, length, and MOD-97 checksum with a full component breakdown — no data leaves your browser.
IBAN Validator is a free online tool that instantly checks whether an IBAN (International Bank Account Number) is structurally correct. It validates the country code, checks the MOD-97 checksum algorithm, and breaks down the IBAN into its individual components — all without sending any data to a server.
What Is an IBAN?
An IBAN is a standardized international numbering system used to identify a bank account across national borders. It was developed by the International Organization for Standardization (ISO) and the European Committee for Banking Standards (ECBS). An IBAN consists of:
- Country code — 2-letter ISO 3166-1 alpha-2 country code
- Check digits — 2-digit number calculated using the MOD-97 algorithm
- BBAN — Basic Bank Account Number, which includes the bank code, branch code, and account number in a country-specific format
How Validation Works
This tool performs full IBAN validation in three steps:
- Format check — Verifies the IBAN contains only valid characters (letters and digits) and matches the expected structure.
- Length check — Confirms the total length matches the official length for that country (e.g. 22 characters for the UK, 22 for Germany).
- MOD-97 checksum — Rearranges the IBAN (moves the first 4 characters to the end), converts letters to their numeric equivalents (A=10, B=11 … Z=35), then divides the resulting number by 97. A valid IBAN always yields a remainder of 1.
| Step | What It Checks |
|---|---|
| Format | Valid characters, minimum structure |
| Length | Country-specific expected length |
| MOD-97 | Mathematical checksum (remainder must equal 1) |
IBAN Lengths by Country (Examples)
| Country | Code | Length |
|---|---|---|
| Germany | DE | 22 |
| United Kingdom | GB | 22 |
| France | FR | 27 |
| Turkey | TR | 26 |
| Spain | ES | 24 |
| Netherlands | NL | 18 |
| Italy | IT | 27 |
| Poland | PL | 28 |
| Norway | NO | 15 |
| Malta | MT | 31 |
The tool supports over 75 countries. If a country is unrecognised, the checksum is still verified.
How to Use
- Paste or type an IBAN — Spaces are ignored automatically; the tool normalises input.
- Read the result — A green "VALID" badge means the format and checksum both pass. Red "INVALID" shows the specific reason (wrong length, bad checksum, or invalid characters).
- Check the breakdown — View the country, check digits, BBAN, and the correctly formatted paper version.
- Try an example — Use the "Try an example" button to cycle through real-format sample IBANs from different countries.
FAQ
Does this tool verify if the bank account actually exists?
No. IBAN validation only checks the format and mathematical checksum. A structurally valid IBAN may belong to a closed or non-existent account. Always confirm account details directly with your bank or the recipient.
Is my IBAN data saved or transmitted?
No. All validation happens entirely in your browser using JavaScript. Your IBAN is never sent to any server or stored anywhere.
Why does IBAN validation use MOD-97?
The MOD-97 algorithm was chosen because it detects all single-digit errors and most transposition errors (two adjacent digits swapped). It provides a strong but lightweight integrity check that can run without network access.
What is a BBAN?
BBAN stands for Basic Bank Account Number. It is the country-specific part of the IBAN that follows the country code and check digits. Its format and length vary by country — for example, a UK BBAN contains the sort code and account number, while a German BBAN contains the bank code (BLZ) and account number.
Can I validate IBANs from non-European countries?
Yes. The IBAN standard has been adopted by many countries outside Europe, including Turkey, Saudi Arabia, UAE, Brazil, Pakistan, and more. This tool supports all countries that have officially adopted the IBAN format.