Validator · ISO 13616 mod-97 · 30 countries

IBAN validator — check in a second.

Paste an IBAN — the validator checks the ISO 13616 mod-97 checksum and the country length. For Slovak IBANs we also show the bank name, BIC code, prefix and account number. Nothing is sent anywhere — everything runs in your browser.

Zadajte IBAN s medzerami alebo bez, malými alebo veľkými písmenami, pomlčkami či lomkami — kalkulačka si formát normalizuje sama. Funguje pre SK, CZ, AT, DE, PL a všetky bežné európske krajiny.

Zadajte IBAN do poľa naľavo — kontrolu spustíme okamžite.

Overenie kontroluje kontrolný súčet (ISO 13616 mod 97) a dĺžku podľa krajiny. Pri zhode s číselníkom slovenských bánk zobrazíme aj názov banky a BIC kód.

Embed the validator

Embed code for your site.

Copy the HTML below and paste it into your blog, internal wiki or helpdesk page. The validator runs in an iframe and checks the IBAN purely in the browser.

Free to use. When quoting, please keep the attribution link „via 1FAKTURA“ under the tool.

<div style="max-width:560px;margin:0 auto">
  <iframe src="https://1faktura.sk/nastroje/iban-overovac/embed" width="100%" height="380" style="border:0;border-radius:16px" title="IBAN validator – 1FAKTURA" loading="lazy"></iframe>
  <p style="font:12px/1.6 system-ui,sans-serif;text-align:center;margin:8px 0 0">
    <a href="https://1faktura.sk/nastroje/iban-overovac" target="_blank" rel="noopener">IBAN validator</a>
    · <a href="https://1faktura.sk/slovnik/iban" target="_blank" rel="noopener">1FAKTURA</a>
  </p>
</div>

Embed preview: /nastroje/iban-overovac/embed

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Invoice online in 1 minute

1FAKTURA issues a Slovak invoice with verified IBAN and QR PAY automatically.

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Questions about the IBAN validator

Frequently asked questions
about IBAN verification.

Something doesn't match? Write to us — we reply within 4 business hours.

info@1faktura.sk
What does this validator check?
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Three things: (1) IBAN structure — 2 country letters + 2 digits + alphanumeric BBAN; (2) length — fixed per country in ISO 13616 (SK = 24 chars, CZ = 24, AT = 20, DE = 22…); (3) the mod 97 checksum, which must yield remainder 1 after rearranging characters and converting letters to digits.
Why can a format-valid IBAN still be wrong?
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The validator confirms the IBAN is mathematically correct — i.e. the number couldn't have been produced by a one-digit typo. But it doesn't verify that the account exists, that it belongs to a specific person, or that it's active. For larger payments, always confirm the recipient's name in your internet banking.
Which countries does the validator work for?
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All countries that use IBAN under ISO 13616 (around 80 countries including the EU, the United Kingdom and most of the Middle East). Per-country length checks cover 30 European countries. For the rest only the checksum is verified.
How does this differ from a bank's validator?
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When you submit a payment, the bank verifies the account actually exists and in some cases shows the recipient name — we can't do that. Our tool is a fast offline check: it catches typos before you submit a payment or publish an IBAN on an invoice.
Is my data sent anywhere?
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No. The whole computation runs in JavaScript in your browser. No data is sent to our server or to analytics. You can verify this yourself in Developer Tools — no network requests.
Can I embed the validator on my site?
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Yes, an embed version is available at /nastroje/iban-overovac/embed. Copy the iframe code from the „Embed the validator“ section below and paste it onto your page. Free to use — just keep the attribution link.
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