Czech IBAN — format, length, example & validator

How a Czech IBAN is structured

A Czech Republic IBAN is read left to right in three blocks. The first two characters are the ISO 3166 country code CZ, which tells the receiving bank the account is in Czech Republic. The next two characters are MOD 97-10 check digits that protect against typos. The remaining 20 characters form the BBAN (Basic Bank Account Number), which Czech Republic splits into 3 fields: 4 digits, then 6 digits, then 10 digits. Because the BBAN layout is fixed for Czech Republic, the validator can check both the total length (24 characters) and the internal structure of every CZ IBAN.

Czech IBAN example

Below is a sample Czech Republic IBAN that passes all three validation layers (character set, 24-character length, and MOD 97 check digits). It is a synthetic test value for integration testing and form demos — never send money to it. The breakdown shows how the CZ country code, check digits, and BBAN fields fit together for a real Czech Republic account.

Common Czech banks and IBAN format examples

Bank names and BICs help you identify the receiving institution, but they do not change the national IBAN layout. A Czech IBAN always has 24 characters and follows 4!n6!n10!n; the bank identifier is embedded in the first BBAN field shown in the table below. The three commonly encountered banks listed here are useful starting points when you are checking payment instructions: Ceska sporitelna, Komercni banka. Always copy the exact IBAN and BIC supplied by the beneficiary, because a bank can use different codes for its head office, a regional office, or a specialist payment branch. The examples are deliberately synthetic format fixtures. CZ6201230123450123456789 demonstrates the country length and checksum, but it is not an account at Ceska sporitelna or any other bank. A real Czech IBAN example must come from the account holder or the bank's own statement. Never infer an account number by combining a public BIC with random digits: that can pass a mathematical checksum while still pointing to no account, or to the wrong beneficiary. When a payment form asks for a Czech IBAN, enter the two-letter country prefix and check digits exactly as issued, remove display spaces if the form requires a continuous value, and verify the beneficiary name. Compare the total length (24) and the BBAN field boundaries with the pattern on this page. If the receiving bank gives you an 8-character BIC, do not append a branch suffix yourself; if it gives an 11-character BIC, preserve all three branch characters. For high-value transfers, ask the bank to confirm whether it wants a head-office BIC or a branch-specific BIC before submitting the wire. The most common Czech formatting traps are copying a domestic account number instead of the IBAN, dropping leading zeroes in a bank or account field, and mistaking a visually similar country prefix. Spaces are harmless when this site's checker cleans input, but they may count as characters in older payment portals. A structurally valid result only proves the ISO 13616 format and MOD 97 check digits; it does not prove that the account exists or that the beneficiary details are correct. Validate first, then confirm the full payment instruction with the recipient's bank.

For an inbound international transfer, request four pieces of information from the beneficiary: the legal account name, the complete Czech IBAN, the receiving bank's BIC/SWIFT code, and the bank's address if the sending portal asks for it. Start by validating the IBAN without changing any characters. The first two letters must be CZ; the next two digits are check digits, not part of the domestic account number. Then compare the 24-character length and the BBAN fields. A payment can be rejected when a sender enters a domestic clearing code in the IBAN field, leaves out a leading zero, or pastes a BIC into the account-number field. If the form offers separate fields for bank code, branch code, and account number, follow the bank's instructions rather than splitting the IBAN by guesswork. The pattern 4!n6!n10!n is a validation guide, not permission to manufacture account data. Some banks route international payments through a central office even when the beneficiary uses a local branch; others require a branch-specific BIC. Confirm the routing choice with the recipient before sending, and keep a copy of the submitted value so support staff can trace a rejected transfer. For recurring payments, store the normalized IBAN (uppercase letters, no spaces) and display it in groups of four for humans. Revalidate after any edit, because one changed character alters the MOD 97 remainder. If the checker reports a valid result but the bank rejects the transfer, contact the bank: format validation cannot see sanctions screening, account status, currency restrictions, name matching, or correspondent-bank requirements. These operational checks are why a careful payment workflow uses both an IBAN checker and the bank's official instructions.

How Czech IBAN check digits work

The two check digits at positions 3–4 of a Czech Republic IBAN are computed with the MOD 97-10 algorithm defined by ISO 13616. To verify them, the IBAN is rearranged so the BBAN comes first and the country code plus check digits go last, letters are converted to numbers (A = 10, B = 11, …, Z = 35), and the resulting large integer is divided by 97. A valid CZ IBAN always leaves a remainder of 1. This single check catches every single-digit typo and most adjacent-digit swaps, which is why a one-character mistake is enough to make a Czech Republic IBAN fail validation instantly — and why you should always validate before wiring money.

Czech IBAN and SWIFT codes

To receive an international wire into Czech Republic, the sender usually needs both your IBAN and the SWIFT/BIC code of your bank. The IBAN identifies your account; the SWIFT code identifies the bank. Once you have validated your CZ IBAN on this page, look up the receiving bank's SWIFT code on the Czech Republic SWIFT codes page to complete the wire instructions.

Czech IBAN FAQ

How long is a Czech Republic IBAN?

A Czech Republic IBAN is always 24 characters long: 2 letters for the country code (CZ), 2 MOD 97 check digits, and a 20-character BBAN. Any Czech Republic IBAN that is shorter or longer than 24 characters is invalid.

What country code does a Czech Republic IBAN start with?

A Czech Republic IBAN starts with the ISO 3166 country code CZ. The first two characters are always CZ, followed by two check digits, then the country-specific BBAN.

How do I validate a Czech Republic IBAN?

Paste the IBAN into the validator on this page — it checks the character set, the 24-character length, and the MOD 97 check digits, all in your browser. You can also load the worked example to see a valid CZ IBAN pre-filled.

Does a valid Czech Republic IBAN mean the account exists?

No. Validation only confirms the IBAN is structurally well-formed and the check digits are correct per ISO 13616. It does not verify the account exists, is open, or belongs to anyone. Always confirm with the recipient or their bank before sending money.

What is the BBAN structure for Czech Republic?

The Czech Republic BBAN is 20 characters and follows the ISO 13616 pattern 4!n6!n10!n: 4 digits (0–9), then 6 digits (0–9), then 10 digits (0–9). The BBAN layout is fixed for Czech Republic, so the validator can check the internal structure of every CZ IBAN, not just the total length.

Do I need a SWIFT code as well as an IBAN for Czech Republic?

For most cross-border transfers into Czech Republic you need both: the IBAN identifies the account, and the SWIFT/BIC code identifies the bank. Validate the CZ IBAN here, then look up the bank's SWIFT code separately.