IBAN Validator
Check whether an IBAN is structurally valid and see its country, check digits and bank identifier · free, no signup
How IBAN Validator works, step by step
Paste an IBAN (spaces are ignored automatically).
Download itSee whether the checksum and length are valid for its country.
Free IBAN Validator
An IBAN (International Bank Account Number) is a standardized format many countries use for cross-border bank transfers, built from a country code, two check digits, and a country-specific bank/branch/account identifier, all defined by the ISO 13616 standard. Paste an IBAN into this tool and it performs the real MOD-97 checksum calculation defined by the standard — rearranging the string, converting letters to numbers, and checking the remainder equals 1 — to tell you whether the check digits are actually valid, not just whether the string looks roughly IBAN-shaped.
It also identifies the country from the two-letter prefix, shows the expected length for that country (IBAN lengths are fixed per country), and breaks the remaining characters into the check digits and the country-specific BBAN (basic bank account number) portion so you can see the real structure, not just a pass/fail result.
Key features
Real MOD-97 checksum, not a format guess
Performs the actual ISO 13616 check-digit algorithm used by real banking systems.
Country and expected length lookup
Confirms the IBAN matches its country's fixed, defined length.
Structural breakdown
Shows the country code, check digits and remaining account identifier separately.
Fully offline
No bank connection is made or needed — this only validates structure and checksum, not that the account actually exists.
How to use it
- Paste an IBAN (spaces are ignored automatically).
- See whether the checksum and length are valid for its country.
- Review the structural breakdown of country code, check digits and account identifier.
Worked example
Example
DE89 3704 0044 0532 0130 00 -> valid German IBAN, 22 characters (correct length for DE), check digits 89 pass the real MOD-97 calculation.
Who uses this tool
Finance and accounting teams
Catch a mistyped IBAN before submitting an international payment.
Developers building payment or onboarding forms
Validate real IBAN structure client-side before hitting a payment API.
Anyone receiving or sending international transfers
Double-check an IBAN a client or vendor sent looks structurally correct.
Tips for the best results
- A valid checksum confirms the IBAN is structurally well-formed — it does not confirm the account actually exists or belongs to the person or business you expect.
- IBAN length is fixed per country; a right-looking IBAN with the wrong number of characters for its country code is invalid even if some digits look plausible.
- Always keep spaces or formatting from the source out of your final saved copy inconsistently — this tool ignores spaces automatically when checking, but confirm your bank's form does too.
Common mistakes to avoid
- Assuming a correctly formatted-looking IBAN is automatically valid without the checksum actually passing — a single mistyped digit is exactly what the check digits are designed to catch.
- Treating checksum validity as proof of account ownership or existence — it only proves the number is structurally well-formed.
- Not accounting for country-specific fixed IBAN lengths, which can vary from 15 to 34 characters depending on the country.
Why use AZRS QuickFix?
It is 100% free, needs no signup and has no watermark or usage limits. The tool runs in your browser, so what you type stays on your device, and it works on phones, tablets and desktops. New tools are added every week — bookmark this page or browse the full QuickFix toolbox.
Frequently asked questions
What does IBAN checksum validation actually prove?
That the number is structurally well-formed according to the ISO 13616 MOD-97 algorithm — it catches typos and formatting mistakes, but does not confirm the account exists or is owned by a specific person.
Why do IBANs have different lengths in different countries?
Each country defines its own fixed IBAN length as part of the standard, based on its national bank account numbering system — this tool checks the entered IBAN against the expected length for its country code.
What are the two check digits for?
They're calculated using the MOD-97 algorithm over the rest of the IBAN and let systems detect most typing or transcription errors without contacting a bank.
Does this confirm the account is real and active?
No — only the account holder's bank can confirm that; this tool only validates structure and checksum offline.
Is my IBAN sent anywhere?
No, validation happens entirely in your browser with plain arithmetic.
Is this free?
Yes, unlimited checks, no signup.