Open the IBAN Validator
Paste an IBAN to validate its real MOD-97 checksum, see the country it belongs to, and break down its structure into check digits.
- Free to use
- No signup
- Nothing to install
- Runs in your browser
DE89 3704 0044 0532 0130 00 -> valid German IBAN, 22 characters (correct length for DE), check digits 89 pass the real MOD-97 calculation.Open the IBAN Validator
Illustration. Open the tool for the real thing.
See it in action
The IBAN Validator with sample data entered and the result showing.
What is the 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.
3 steps to your result
Open the tool and follow along. Nothing to install.
What you get
Performs the actual ISO 13616 check-digit algorithm used by real banking systems.
Confirms the IBAN matches its country's fixed, defined length.
Shows the country code, check digits and remaining account identifier separately.
No bank connection is made or needed — this only validates structure and checksum, not that the account actually exists.
AZRS tools are free to open and use.
It opens in your browser, so there is nothing to download.
Used for
Pick one to see how it fits.
Finance and accounting teams
Catch a mistyped IBAN before submitting an international payment.
Try it freeDevelopers building payment or onboarding forms
Validate real IBAN structure client-side before hitting a payment API.
Try it freeAnyone receiving or sending international transfers
Double-check an IBAN a client or vendor sent looks structurally correct.
Try it freeHow it compares
A plain look at this tool next to the usual alternative.
| This utility | Desktop software | |
|---|---|---|
| Install | Nothing to install | Usually an app or program to install |
| Account | No signup | Depends on the product |
| Cost | Free to use | Free or paid, depends on the product |
| Where it runs | In your browser tab | On your computer |
Questions people ask
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.
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Check whether an IBAN is structurally valid and see its country, check digits and bank. Free to use.
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