IBAN Validator

Before you send an international wire transfer, one mistyped character in an IBAN can bounce the payment, trigger bank investigation fees of €15–50, and delay your money by days. ToolsPopper's free IBAN validator catches those errors in under a second: paste any International Bank Account Number and it instantly verifies the country code, length, character structure, and the ISO 13616 mod-97 check digits — the same math banks run before accepting a SEPA payment.

What does the IBAN Validator check?

A complete IBAN validation involves four independent checks, and this tool runs all of them:

• Country code — the first two letters must be a real ISO 3166 country that participates in the IBAN scheme (DE, GB, FR, ES, NL, and about 80 others).
• Length — every country fixes its own exact length. A German IBAN is always 22 characters; a French one is always 27. A single missing digit fails immediately.
• Structure — each country defines which positions are digits and which are letters (for example, UK IBANs contain a 4-letter bank code after the check digits).
• Mod-97 checksum — the two check digits in positions 3–4 must satisfy the ISO 7064 mod-97-10 algorithm. This is the test that catches transposed or mistyped characters with 99% reliability.

Everything runs locally in your browser. The IBANs you paste are never transmitted, logged, or stored — which matters when you're checking real customer or supplier banking details.

How to validate an IBAN

1. Paste the IBAN into the input field — with or without spaces, upper or lower case.
2. Click Validate. The tool normalizes the input and runs all four checks.
3. Read the result: a valid IBAN shows a green confirmation; an invalid one tells you it failed so you can re-check the source document.
4. Repeat for as many IBANs as you need — there is no daily cap and no account required.

How the mod-97 check digit algorithm works

The checksum test looks intimidating but is simple arithmetic. Take GB82 WEST 1234 5698 7654 32 as a worked example:

1. Move the first four characters (GB82) to the end: WEST12345698765432GB82.
2. Replace every letter with two digits (A=10 … Z=35): W→32, E→14, S→28, T→29, G→16, B→11.
3. Divide the resulting long number by 97. If the remainder is exactly 1, the IBAN is valid.

Because a single wrong character almost always changes that remainder, the mod-97 test catches virtually all typos — which is why the ECB made it mandatory for every SEPA transaction.

IBAN lengths by country

Wrong length is the most common reason an IBAN fails validation. These are the lengths for the countries we see checked most often:

• Germany (DE) — 22 characters
• United Kingdom (GB) — 22 characters
• France (FR) — 27 characters
• Spain (ES) — 24 characters
• Italy (IT) — 27 characters
• Netherlands (NL) — 18 characters
• Switzerland (CH) — 21 characters
• United Arab Emirates (AE) — 23 characters
• Norway (NO) — 15 characters (the shortest)
• Malta (MT) / Saint Lucia (LC) — 31–32 characters (the longest)

When should you validate an IBAN?

• Before international wire transfers — catch typos before your bank charges an amendment or return fee.
• Checkout and onboarding QA — test SEPA payment fields in staging with valid and deliberately broken IBANs. Pair this validator with our IBAN Generator to produce structurally valid test numbers.
• Bulk data migration — spot-check IBAN columns after importing supplier or payroll records into a new ERP.
• Invoice fraud screening — a supplier "new bank details" email with an IBAN that fails validation is a red flag worth a phone call.
• US payment workflows — the United States doesn't use IBAN; for domestic US account verification use our Routing Number Validator instead. For EU tax IDs, there's a separate VAT Validator.

ToolsPopper vs IBAN.com and bank-provided checkers

Sites like IBAN.com and IBAN Calculator offer solid validation with bank-name and BIC lookup — but the free tiers meter your checks, and every IBAN you enter is processed on their servers.

• Unlimited free validation — no daily quota, no premium tier, no API key.
• 100% private — checksum math runs on your device; real banking data never touches our servers.
• No signup — paste and validate in the same second you land on the page.
• Test-data friendly — validate sandbox IBANs alongside real ones without uploading either.
• The trade-off — we deliberately don't do bank-name/BIC lookup, since that requires sending your IBAN to a remote directory. If you need to confirm the receiving bank's identity, use your bank's own verification-of-payee service.