How do I look up a Czech company by IČO from an API?

Call GET /companies/search?country=CZ&company_number=45274649. A CZ prefix is optional and a shorter number is read with its leading zeros restored. A malformed number is a 400 validation error; a number that is well-formed but fails the mod-11 check is flagged and still looked up.

Is the IČO check enforced?

No, it is advisory. The weights are 8, 7, 6, 5, 4, 3, 2 over the first seven digits, but the register holds live companies whose IČO fails the check, so they are served. Only malformed input (letters, the wrong length, a 9 or 10 digit birth number) is refused.

Can I look up a Czech company by VAT number?

No. The register data carries no VAT number and the DIČ is not served, so a vat search for the Czech Republic is refused. vat_number is null on every Czech record. To check a number against VIES, use GET /vat/ followed by the number.

Does the Czech record include officers, company events or insolvency notices?

Company events yes; officers and insolvency notices no. The Czech record is company-level. There are no officers, partners, shareholders or beneficial owners, no registry-compliance signal and no financial statements. Register-change events (name, status, legal form, registered address and share capital, dated when the change first appears in the register data, none before the first load in October 2026) and monitoring are available. The Czech Republic is not one of the twelve insolvency markets: insolvency and bankruptcy show in the status.

Which Czech entities does it cover?

Commercial legal persons: s.r.o., a.s., v.o.s., k.s., cooperatives, SE, SCE and EEIGs. Sole traders (OSVČ) and other natural persons, associations, foundations, trust funds, owners’ associations (SVJ) and branches are never served, so a lookup of one returns nothing even though it exists.

Can I call the API from the browser?

You can, but a key in the browser is public. Proxy the search through your server, as in the sample above. Rate limits are per key.

Is there a way to try it before signing up?

Yes: the free Czech IČO lookup runs the same call with a shared key.

Czech company data API: look up and validate an IČO

A customer types a Czech IČO or the first letters of a name; your form fills in the legal name, legal form, status and registered address from the Czech public register (Veřejný rejstřík). One key and one response shape, the same as every other country the API covers.

Company records from the public register of the Czech Republic (Veřejný rejstřík, Ministry of Justice ISVR open data) and the Czech Statistical Office’s Register of Economic Entities (RES): legal name, legal form, status (including liquidation, insolvency, bankruptcy and restructuring), registered address with postal code, city and region (kraj), registration date, share capital and the CZ-NACE 2025 activity code; with register-change events and monitoring, but no officers, no registry-compliance signal, no VAT number and no insolvency notices. Commercial legal persons only: sole traders and other natural persons, associations, foundations and branches are never served.

What the Czech record gives your product

Exact match on the IČO: company_number=45274649 with country=CZ. A CZ prefix is optional and a shorter number is read with its leading zeros restored; the mod-11 check is advisory, so a number that fails it is flagged and still looked up.
Autocomplete by name: a normalised, partial match ranked by a match score, one call per keystroke.
The fields a form needs: legal name, legal form, status, registered address with postal code, city and region, share capital and the CZ-NACE 2025 activity code.
The court file in registry_details: registration_court, registration_number (for example B 1581), source_register and status_code.

What the Czech Republic does not carry

No officers, partners, shareholders or beneficial owners, no registry-compliance signal, no VAT number (a vat search is refused), no insolvency notices and no financial statements. Register-change events and monitoring are available. Sole traders and other natural persons are never served.

Pricing

Free — 14-day trial. 500 credits in total, 10 requests/minute, card required, nothing charged for 14 days. Subscribing keeps the same key working. Then Starter at €9.99/month, Professional at €29.99/month and Scale at €99.99/month, monthly or annual.

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Contains data from the public registers of the Czech Republic (Ministry of Justice, ISVR open data) and the Czech Statistical Office (RES, CC BY 4.0). Adapted by Prometiam.

What the Czech record gives your product

Field	What it holds for the Czech Republic
`company_number`, `identifiers`	The IČO, 8 digits with leading zeros: `45274649`. `identifiers` lists it as type `ico`, with the file number as `registration_number`.
`company_name`	The name as registered.
`legal_form`, `local_legal_form`, `local_legal_form_name`	The standard abbreviation (a.s., s.r.o.), the register’s form code and its name (Akciová společnost).
`status`, `stage`, `local_status`	The standard reading of the register’s state, its stage and the register’s own value.
`address`, `postal_code`, `city`, `region`	The registered address; `region` holds the region (kraj) from the Czech Statistical Office.
`capital_amount`, `capital_currency`	The registered share capital, in CZK or in EUR for a company that registers in euro.
`activity_code`, `activity_code_scheme`	The CZ-NACE 2025 code (1 to 5 digits) and the scheme `CZ-NACE-2025`.
`registry_details`	`registration_court`, `registration_number`, `source_register` and `status_code`.
`vat_number`	Always null: the register data carries no VAT number.

Frequently asked questions

How do I look up a Czech company by IČO from an API?: Call GET /companies/search?country=CZ&company_number=45274649. A CZ prefix is optional and a shorter number is read with its leading zeros restored. A malformed number is a 400 validation error; a number that is well-formed but fails the mod-11 check is flagged and still looked up.
Is the IČO check enforced?: No, it is advisory. The weights are 8, 7, 6, 5, 4, 3, 2 over the first seven digits, but the register holds live companies whose IČO fails the check, so they are served. Only malformed input (letters, the wrong length, a 9 or 10 digit birth number) is refused.
Can I look up a Czech company by VAT number?: No. The register data carries no VAT number and the DIČ is not served, so a vat search for the Czech Republic is refused. vat_number is null on every Czech record. To check a number against VIES, use GET /vat/ followed by the number.
Does the Czech record include officers, company events or insolvency notices?: Company events yes; officers and insolvency notices no. The Czech record is company-level. There are no officers, partners, shareholders or beneficial owners, no registry-compliance signal and no financial statements. Register-change events (name, status, legal form, registered address and share capital, dated when the change first appears in the register data, none before the first load in October 2026) and monitoring are available. The Czech Republic is not one of the twelve insolvency markets: insolvency and bankruptcy show in the status.
Which Czech entities does it cover?: Commercial legal persons: s.r.o., a.s., v.o.s., k.s., cooperatives, SE, SCE and EEIGs. Sole traders (OSVČ) and other natural persons, associations, foundations, trust funds, owners’ associations (SVJ) and branches are never served, so a lookup of one returns nothing even though it exists.
Can I call the API from the browser?: You can, but a key in the browser is public. Proxy the search through your server, as in the sample above. Rate limits are per key.
Is there a way to try it before signing up?: Yes: the free Czech IČO lookup runs the same call with a shared key.