How Do You Validate an IBAN? A Free, Private Checker
Updated 2026-06-27
To validate an IBAN, paste it into a checker that runs the ISO 7064 mod-97 checksum and confirms the country code, check digits and length — the IBAN Validator & Parser does all of this instantly in your browser, with nothing uploaded. A green result means the number is mathematically well-formed; a red result tells you exactly what is wrong.
What "valid" actually proves
An IBAN (International Bank Account Number) packs a country, a two-digit checksum and a domestic account number into one string. Validation answers a narrow but important question: is this number internally consistent?
- The first two letters must be a country code, followed by two check digits.
- The total length must match that country's fixed length (German IBANs are 22 characters, UK 22, French 27, and so on).
- Rearranging and converting the IBAN to a number must leave a remainder of 1 when divided by 97.
That last step is the clever part: the mod-97 algorithm catches virtually every single-digit typo and most transpositions. What it cannot do is confirm the account is open or that money will arrive — only the receiving bank knows that. A valid IBAN is a well-formed IBAN, nothing more.
Validate one step by step
Using the IBAN Validator & Parser takes seconds:
- Paste the IBAN into the field. Spacing and letter case do not matter — de89 3704 0044 0532 0130 00 and DE89370400440532013000 are treated the same.
- Read the banner. Pass means structure and checksum both hold. Fail tells you whether it was the format, the length, or the checksum.
- Check the parsed tiles: country, check digits, total length and BBAN length.
- Copy the pretty (grouped-in-fours) form for a form, or copy just the BBAN if a system wants the domestic part on its own.
Reading common errors
The error message points straight at the problem:
- "starts with 2 letters, 2 digits…" — the basic shape is broken, usually a stray character or a missing country code.
- "… IBANs are N characters; this is M" — you have dropped or duplicated a digit. The expected length is shown so you can hunt for the missing one.
- "check digits do not match (failed mod-97)" — the structure is fine but a character is wrong. This is the typo-catcher in action.
Why do it in your browser
A bank account number is sensitive data. Many online IBAN checkers send what you type to a server, where it may be logged. This tool runs the entire calculation locally — the mod-97 math happens on your device and nothing is transmitted, stored or shared. Close the tab and there is no trace.
That privacy guarantee matters most when you are handling someone else's details: a client's payment info, a vendor's banking form, or a batch of numbers from a spreadsheet.
After validating
Once an IBAN checks out, you often need to share full contact and payment details cleanly. The vCard Generator builds a standards-compliant contact card you can attach to an email or a QR code, so the recipient saves your name, company and details in one tap. Pair the two: validate the IBAN here, then package your contact info there — both run privately in the browser.