Czechia DIČ validator
How the DIČ format works
- Format
- CZ + 8 to 10 digits
- Example
- CZ12345678
Things to watch for
- Length varies from 8 to 10 digits depending on entity type
- This tool checks the format only; no check-digit validation is performed
^CZ[0-9]{8,10}$A Czech VAT number is called a DIČ (Daňové identifikační číslo), and its length isn’t fixed the way most EU countries’ numbers are: “CZ” is followed by anywhere from 8 to 10 digits, depending on who’s registered. Companies generally get an 8-digit number tied to their IČO business ID; individuals and sole traders are often assigned a longer one derived from their birth number (rodné číslo), which can stretch the total to 10 digits.
That variability is exactly why a Czech DIČ can look “too short” or “too long” compared to a number you’ve seen before — both are legitimate, and the correct length depends entirely on whether the taxpayer behind the number is a registered company or an individual.
Under the hood
This validator checks for the “CZ” prefix and counts the digits that follow, accepting anything from 8 to 10 as valid — instantly, in your browser, with nothing sent to a server. It’s a structural range check, not a checksum: the Czech Financial Administration’s own check-digit rules aren’t calculated here.
What’s out of scope
A pass tells you the shape is plausible, not that the number is a live registration with the Finanční správa (Czech Financial Administration). Confirm current status through the EU’s VIES lookup before treating it as verified.
Scope: DIČ format and length only — not registration status, filing, or the underlying IČO/rodné číslo validation.
Content last reviewed 2026-07-07.
DIČ FAQ
Why does a Czech DIČ vary between 8 and 10 digits?
Length depends on who holds it: companies typically use an 8-digit IČO-based number, while individuals and sole traders often carry a longer number derived from their birth number (rodné číslo), which can run to 10 digits.
Is DIČ the same as IČO?
Related but not identical. IČO is a company's core business identification number; DIČ is the tax identifier built from it (for companies) or from a birth number (for individuals), always prefixed with 'CZ' for VAT purposes.
Does this tool run the Czech check-digit formula?
No, not currently — it validates the 'CZ' prefix and confirms the digit count falls between 8 and 10, which is a structural check rather than a full checksum.