Czechia · CZ
The Czech VAT number (DIČ)
For a legal person the VAT number is the company number with CZ in front, and ARES hands back the company for free, over a REST API with no account and no key. The catch is that not every Czech number is a legal person.
Format: CZ + 8 to 10 digits
Example: CZ00177041, IČO 00177041
Issued by: the tax office, on VAT registration.
The format
A Czech VAT number carries eight to ten digits after the prefix, and which one depends on who the taxpayer is.
- CZ + 8 digitsA legal person: the digits are its IČO, the company number.
- CZ + 9 or 10 digitsA natural person: the birth number, or a special number.
The eight-digit IČO carries a check digit in last position, computed modulus 11 with weights 8, 7, 6, 5, 4, 3, 2. Short IČOs are left-padded with zeros, 00177041, never 177041.
IČO, DIČ and the file number
The IČO is assigned by the Czech Statistical Office to every business entity at formation and never changes. The DIČ comes into existence only on tax registration; for a legal person it is the same digits with CZ in front.
The distinction that matters: every entity has an IČO, only a registered taxpayer has a DIČ. A non-registered business has a valid IČO and does not exist in VIES.
Third, there is the file number in the commercial register, B 332 at the Municipal Court in Prague, for instance. It has nothing to do with the VAT number.
Finding the company
ARES
ARES, the finance ministry’s register of economic subjects, is what makes Czechia easy: it is public, free and unauthenticated, has a modern REST API, and returns the trade name, seat, legal form, status and (the decisive part) the DIČ itself, alongside the IČO.
Because the VAT number is the company number with the prefix removed, one request resolves it.
The commercial register
justice.cz holds the full public registers including filed documents and annual accounts, free of charge. It is searched by name or IČO.
The register of VAT payers
The Financial Administration publishes a register of VAT payers where you can check whether an entity is registered and whether it is flagged as an unreliable payer, a status ARES does not carry and which has direct tax consequences for a Czech customer.
VIES
Czechia discloses both name and address through VIES. The address arrives on several lines, the middle one often carrying a city district and the last one the postal district.
Czechia-specific pitfalls
- Pad with leading zeros. The IČO is always eight digits;
CZ177041is a mangledCZ00177041. - An IČO does not imply VAT registration. Every entity has one; only registered payers have a DIČ.
- A natural person’s DIČ is longer and derived from the birth number, giving nine or ten digits.
- "Unreliable payer" is a Czech speciality. The number stays valid, but a Czech customer can become liable for the unpaid tax, and VIES says nothing about it.
- ARES is unusual. Most member states do not publish the link between the company number and the tax number at all.
One API, one response shape
Vatlas turns a business tax number into a company record: legal name, national identifier, legal form, status and address. Czechia: the same call and the same response as for every other country covered.
curl "https://api.vatlas.dev/v1/lookup/CZ00177041" \
-H "Authorization: Bearer $VATLAS_KEY"Response:
200 OK
{
"data": {
"vatNumber": "CZ00177041",
"countryCode": "CZ",
"nationalNumber": "00177041",
"nationalId": "00177041",
"name": "Škoda Auto a.s.",
"legalForm": "Akciová společnost (a.s.)",
"status": "active",
"address": {
"line1": "tř. Václava Klementa 869",
"line2": "Mladá Boleslav II",
"postalCode": "293 01",
"city": "Mladá Boleslav",
"country": "CZ"
}
},
"meta": {
"source": "ARES",
"sourceDate": "2026-09-15",
"sourceSince": "2026-09-15",
"sourceUpdatedAt": "2026-09-03T00:00:00.000Z"
}
}meta.source names the register that answered (SIRENE, ARES, VIES…) and meta.sourceDate the day it said so: the publication date of the file for a register we import, the day of the call for one we query live. The shape of the response never changes from one country to the next.
Try it on your own numbers. An email address is all it takes to create an account, with 100 requests a month and a working key in about a minute.
Frequently asked
The Czech VAT number in short
How many digits does a Czech VAT number have?
Eight to ten after the CZ prefix. Legal persons have eight, identical to their IČO; natural persons have nine or ten.
Is the DIČ the same as the IČO?
For a legal person the digits are identical and the DIČ just adds CZ. But every entity has an IČO, while a DIČ exists only after tax registration.
How do I find a company from a Czech VAT number?
Strip the CZ prefix and put the remaining IČO into ARES. It is free, public and returns the name, seat and legal form.
What is an unreliable payer?
A taxpayer the Financial Administration has found in serious breach of its obligations. The VAT number stays valid, but a Czech customer can be held liable for the unpaid tax.
Why does VIES reject a valid IČO?
Because an IČO is not a VAT number. The entity exists but is not registered for VAT, so it is not in VIES.
VAT numbers in other countries
Last updated 28 August 2026.