Before signing a contract with a new supplier, accepting a large order from an unknown buyer, or starting a significant business relationship, it pays to know what public records say about the other party. The Czech Republic operates several free databases that, when combined, paint a surprisingly detailed picture of any economic entity. This article walks you through the four most important ones.

ARES: The Starting Point for Any Check

ARES (Administrativní registr ekonomických subjektů — Administrative Register of Economic Entities) is operated by the Czech Ministry of Finance and serves as a central gateway to data from the commercial register, the trade register, the Czech Statistical Office registry, and other sources. Enter an IČO (business registration number) or company name and you instantly get:

  • Identification data — registered company name, IČO, DIČ (VAT number), date of incorporation, and legal form.
  • Registered address — street, municipality, postcode; useful for verifying invoices or sending legal correspondence.
  • Business activity and NACE code — the CZ-NACE classification shows the primary sector and lets you verify whether the company's stated activity matches what it actually offers.
  • Statutory representatives and shareholders — names of directors or board members, their ownership shares, and signatory authority.
  • Entity status — active, dissolved, in liquidation, or in bankruptcy.

ARES is the first stop in any due diligence process. It takes under a minute and immediately flags basic discrepancies — for example, a registered address that differs from the invoice, or a director whose name does not match the contract.

The Unreliable VAT Payer Register

The Czech Ministry of Finance publishes a list of entities designated as unreliable VAT payers (nespolehlivý plátce DPH). The status was introduced in 2013 to combat VAT carousel fraud. A company ends up on the list after serious or repeated VAT violations — typically unpaid VAT debt or involvement in fraudulent transactions.

Why does this matter to a buyer? Under Section 109 of Czech VAT Act No. 235/2004 Coll., the recipient of a supply becomes jointly and severally liable for the supplier's unpaid VAT if payment was made to a bank account not listed in the official register, or if the buyer knew of the unreliability. In practice, this can add 21 % to the cost of an already-paid invoice. More than 4,700 entities are currently listed — a check takes seconds and can save hundreds of thousands of crowns. A detailed how-to: VAT Payer Reliability in Czechia: What You Must Know.

Insolvency Register ISIR

The insolvency register (isir.justice.cz), operated by the Czech Ministry of Justice, contains all insolvency proceedings since 2008. You can search by a company's IČO or an individual's name. The register tells you:

  • Status of proceedings — whether an insolvency proceeding is open, and at what stage (moratorium, reorganisation, bankruptcy, debt relief).
  • Court documents — judicial decisions, creditor claims, insolvency administrator reports.
  • History — closed proceedings remain in the database, so you can see whether a company survived a past insolvency.

As of August 2026, the register holds records for over 446,000 debtors. Checking ISIR is a non-negotiable step when evaluating a major customer or investment target — a company that looks healthy today may have been in serious financial trouble quite recently.

Contract Register: Public Sector Transparency

Since 2016, Act No. 340/2015 Coll. has required government bodies, municipalities, regions, and state-owned enterprises to publish every contract above CZK 50,000 (excl. VAT) in the contract register (smlouvy.gov.cz). A contract that is not published does not take legal effect. The register contains:

  • Contracting parties and subject matter — who contracted with whom and for what.
  • Contract value — total price or unit price; critical for benchmarking a competitive offer.
  • Date of conclusion and contract duration.
  • Attachments — the full contract text (commercial secrets and personal data may be redacted).

For business intelligence, the contract register is a goldmine: you can quickly find out how much a public institution pays its current suppliers and use that data to build a compelling business case or sharpen your pricing.

Combining the Registers: Due Diligence in 10 Minutes

The four registers only deliver their full value when used together. Recommended workflow:

  1. ARES — verify the IČO, registered address, directors, and entity status.
  2. ADISREG — check whether the company is an unreliable VAT payer and confirm the bank account before paying.
  3. ISIR — search the insolvency register by IČO and by the names of key individuals.
  4. Contract register — if the counterparty is or has been a public-sector entity, or if it contracts with public bodies, review its contract history.

Manually browsing four separate portals is slow and unsustainable at scale. Services like databázekontaktu.cz aggregate data from ARES, the VAT payer register, and the insolvency register, letting you screen an entire portfolio of business partners at once — without switching between browser tabs. Define the segment upfront with an export of companies by industry.

Conclusion

Czech public registers are not just a bureaucratic formality — they are practical tools that can protect your business from insolvent partners, joint-and-several VAT liability, or contracts signed with a company already in liquidation. All it takes is knowing where to look and how to join the dots. Now you do. The full Czech company database with contacts and pricing are in the company database subscription section.