Converter · ISO 13616 · 13 Slovak banks

IBAN from account number — Slovak converter.

Convert an old Slovak account number (prefix-number/bank code) to an international IBAN in a second. The result is mathematically verified by ISO 13616 mod-97. No signup, nothing is sent anywhere — everything runs in your browser.

Pri kopírovaní zo starého výpisu obvykle uvidíte tvar 19-8742637541/1200 — predčíslie (pred pomlčkou) a číslo účtu (medzi pomlčkou a lomkou). Lomka oddeľuje kód banky.

Doplňte zostávajúce polia

Zadajte aspoň číslo účtu a kód banky.

Výpočet je čisto matematický (ISO 13616). Pred odoslaním platby na väčšiu sumu IBAN vždy overte cez bankový internet-banking — slovenské banky vám pri zadaní platby zobrazia meno príjemcu.

How a Slovak IBAN is composed

24 characters, 4 fields, one check.

Conversion from the old format is no magic — a Slovak IBAN exactly mirrors the original account number, only aligned and topped with an internationally verifiable checksum.

The algorithm is defined by ISO 13616 and ECBS EBS204. The Slovak details are described by the National Bank of Slovakia.

  1. SK

    Country code (2 letters)

    Fixed identifier for the Slovak Republic. Always „SK“ for any Slovak bank account.

  2. 31

    Check digits (2 digits)

    Computed from BBAN per ISO 13616 mod-97. Our converter generates them itself — you never enter them.

  3. 1200

    Bank code (4 digits)

    Assigned by the NBS. 0900 = SLSP, 0200 = VÚB, 1100 = Tatra, 7500 = ČSOB. In the old account number it sits after the slash.

  4. 000019

    Prefix (6 digits, padded with zeros)

    A historical client identifier within the bank. Modern accounts don't have one — the field is padded with zeros.

  5. 8742637541

    Base account number (10 digits, padded with zeros)

    The actual account number. If shorter than 10 digits, it's left-padded with zeros. This is „8742637541“ from the NBS example.

Embed the converter

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Copy the HTML below and paste it into your blog, help page or internal wiki. The converter runs in an iframe with no other dependencies.

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<div style="max-width:560px;margin:0 auto">
  <iframe src="https://1faktura.sk/nastroje/iban-z-cisla-uctu/embed" width="100%" height="520" style="border:0;border-radius:16px" title="IBAN from account number – 1FAKTURA" loading="lazy"></iframe>
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    <a href="https://1faktura.sk/nastroje/iban-z-cisla-uctu" target="_blank" rel="noopener">IBAN from account number</a>
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Questions about the IBAN converter

FAQ
about Slovak IBAN.

Something doesn't add up? Write to us — we'll reply within 4 hours on a business day.

info@1faktura.sk
How is a Slovak IBAN composed?
+
A Slovak IBAN has 24 characters: country code SK (2 chars) + 2-digit check sum + 4-digit bank code + 6-digit prefix (left-padded with zeros) + 10-digit base account number (left-padded with zeros). 20 BBAN digits in total.
What do I do if I don't have a prefix?
+
Modern accounts opened after 2014 usually don't have a prefix. Leave the field empty — the calculator pads it with six zeros per the NBS standard. The resulting IBAN is valid.
What's the difference between IBAN and BIC?
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IBAN identifies a specific account; BIC (or SWIFT) identifies a bank. For SEPA payments within the EU the IBAN is usually enough. For non-SEPA international payments some banks require BIC too — our converter fills it automatically for the 13 supported Slovak banks.
Why does the yellow „NBS checksum failed“ warning appear?
+
Besides the IBAN mod-97 check, the National Bank of Slovakia defines a weighted checksum for the prefix and account number (mod 11). If you see the warning, the IBAN is mathematically correct (payments will go through) but you likely mistyped one digit. Double-check the statement.
Does the converter work for every Slovak bank?
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Yes — the IBAN math depends only on the bank code. Our list contains 13 of the most used banks directly (SLSP, VÚB, Tatra, ČSOB, Poštová banka, UniCredit, Prima banka, OTP, Fio, 365.bank, Privatbanka, J&T, mBank).
Can I embed the converter on my own site?
+
Yes, an embed version is available at /nastroje/iban-z-cisla-uctu/embed for iframes. Free to use; just keep a small attribution link under the tool.
Is it safe? Is my data sent anywhere?
+
The calculation runs 100 % in your browser — nothing is sent to our server, to any database or to analytics. You can inspect the calculator's source code in Developer Tools yourself.
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