Czechia (CZ)
Czech VAT Number Validation
Format, pattern, and checksum algorithm for CZ VAT numbers
Czech VAT numbers (DIČ - Daňové identifikační číslo) can be 8, 9, or 10 digits, with different validation rules depending on the length.
Format vs. Active Validation
This checks format only, not if a VAT number is really registered. Use VatDB's API to verify is a number is really registered and active. VatDB checks official EU and national datasources.
Format Overview
| Property | Value |
|---|---|
| Country Code | CZ |
| Format | 8, 9, or 10 digits |
| Length | 8-10 digits |
| Example | CZ12345678 |
Regex Pattern
^CZ[0-9]{8,10}$
Checksum Algorithm
8 Digits (Legal Entities)
def validate_cz_vat_8(number):
weights = [8, 7, 6, 5, 4, 3, 2]
total = sum(int(d) * w for d, w in zip(number[:7], weights))
check = (11 - (total % 11)) % 10
return check == int(number[7])
9-10 Digits (Individuals)
For individuals, the VAT number is based on the birth number (rodné číslo): - Format: YYMMDD + sequence number - For females, 50 is added to the month - The entire number must be divisible by 11 (with some exceptions for older numbers)
def validate_cz_vat_individual(number):
# Basic format check
if len(number) == 9:
# Old format (before 1954) - just check format
return number.isdigit()
if len(number) == 10:
# Check divisibility by 11
return int(number) % 11 == 0
Frequently Asked Questions
How do I verify a Czech VAT number (DIČ)?
Czech VAT validation depends on length: 8 digits (companies) use weighted checksum, 9-10 digits (individuals) are based on birth numbers. Use VatDB's API for official verification against EU and national databases.
What does a Czech VAT number look like?
A Czech VAT number (DIČ) has format CZ12345678 (8 digits for companies) or CZ1234567890 (9-10 digits for individuals). The length indicates entity type.
How many digits are in a Czech VAT number?
Czech VAT numbers have 8, 9, or 10 digits: 8 digits for legal entities (companies), 9 digits for individuals born before 1954, and 10 digits for individuals born from 1954 onwards.
What is a Czech DIČ number?
DIČ (Daňové identifikační číslo) is the Czech tax identification number used as the VAT ID. For individuals, it's based on the rodné číslo (birth number) which encodes the date of birth.
Why do some Czech VAT numbers have different lengths?
8-digit DIČ numbers are for legal entities. Individual DIČ numbers are based on birth numbers: 9 digits for people born before 1954, 10 digits for those born from 1954. The 10-digit version adds a check digit.
How can I look up a Czech company by VAT number?
VatDB provides real-time VAT validation against official EU and national databases. Get instant verification with company information.
What's the difference between format validation and checking if a VAT number is active?
Passing format validation means the number is correctly structured, nothing more. It could belong to a dissolved company or never have been issued. VatDB confirms actual registration status.