Czech Republic VAT number: format and validation

By Remco from Avatcado

Format

CZ followed by 8, 9, or 10 digits. The local term is danove identifikacni cislo (DIC, Czech).

Pattern: /^\d{8,10}$/

  • 8 digits for legal entities (equal to the company's ICO identification number); 9 or 10 digits for individuals (based on the personal birth number)
  • The DIC is a general tax ID used for all taxes; being in the separate VAT payer register is what makes it a valid VAT number

Example of a registered number: CZ00177041

Check digit

Czech Republic VAT numbers carry a check digit (Weighted MOD 11 (ICO)): For 8-digit company numbers the last digit is a weighted mod 11 check over the first seven digits.

Check a Czech Republic VAT number

Checks route through VIES. Caching is enabled by default. Read the source, original result time and freshness label alongside validity; a cached or stale result does not freshly confirm current registration.

Enter a VAT number to see its registration result, source and freshness

Validate via API

The same validation as an API call, with the example number above:

curl "https://api.avatcado.com/v1/validate?vat_number=CZ00177041" \
  -H "Authorization: Bearer avat_live_your_api_key"
import Avatcado from "@avatcado/node";

const avatcado = new Avatcado("avat_live_your_api_key");
const { data, error } = await avatcado.vat.validate({
  vatNumber: "CZ00177041",
});

if (data?.data.valid) {
  console.log(`Registered: ${data.data.company?.name}`);
}

Free tier includes 500 validations per month. Get an API key or read the API documentation.

How Avatcado validates Czech Republic numbers

  • Primary source: VIES.
  • Company name and address: yes, observed 2026-09-04.
  • When VIES is down: ARES (live on the request) on Pro and Business, then the cached result, then a refunded 503.

See the full coverage table.

Frequently asked questions

What is the VAT registration threshold in the Czech Republic?

Since 1 January 2025 there are two tiers: exceeding CZK 2,000,000 in a calendar year makes you a VAT payer from 1 January of the following year, while exceeding CZK 2,536,500 makes you a payer immediately.

How do I look up a Czech VAT number?

Use the official VAT payer register (Registr platcu DPH) at adisreg.mfcr.cz, which also shows unreliable-payer status. Company identity can be checked in ARES (ares.gov.cz).

How does Avatcado validate Czech Republic VAT numbers when VIES is down?

When VIES cannot answer for Czech Republic because of an availability fault such as MS_UNAVAILABLE or a timeout, eligible Pro and Business checks can use ARES, run by Czech Ministry of Finance; the Free plan can use eligible cache instead. ARES is queried live on the request, so the fallback answer is as current as the authority's own database, and there is no separate snapshot behind it. A confirmed answer includes the registered company name and address that ARES publishes. ARES lookups can only confirm a positive: if the register does not carry the number, or cannot confirm it, Avatcado never reports the number invalid on that basis, and the request moves on to the next step instead. A confirmed fallback answer carries meta.source: "ares" and meta.source_status: "fallback", so your code can tell it apart from a normal VIES confirmation. There is no VIES consultation number attached to it, since only VIES itself issues one, which is why a request that carries requester_vat_number skips the register by default and only reaches it when you pass fallback=true. If ARES also cannot confirm the number, Avatcado can serve an eligible stored result with meta.cached: true and meta.stale: true when it is past the cache window. Requester checks disable stored responses by default; cache=true opts back in. If no eligible source can answer, the request returns a refunded 503 (upstream_member_state_unavailable). Retain the source and original timestamp; stored evidence does not freshly confirm current registration.

Related guides

VAT rate in Czech Republic

The standard VAT rate in Czech Republic is 21%. Reduced rates: 12%, 0%. See all Czech Republic VAT rates.

Sources