Shape, check digit, accepted and refused examples and the API call for IČO in Czech Republic. Every example on this page is run through the same validators as the free identifier validator, so a value shown as accepted is a value the validator accepts.
| Field | Value |
|---|---|
| Register | Veřejný rejstřík (Ministry of Justice), RES |
| Shape | N{7} C |
| Check digit | Advisory. 8 digits, shorter numbers read with leading zeros. Weights 8,7,6,5,4,3,2 over the first 7 digits, r = sum mod 11; check = 1 when r is 0, 0 when r is 1, else 11 minus r. Advisory: a mismatch is a warning. |
| Worked example (accepted) | 45274649 |
| Normalised form | 45274649 |
| Also accepted as input | CZ45274649 |
| A one-character slip | 45274640 is accepted with a warning |
| Regex (normalised form) | ^[0-9]{8}$ |
| API call | GET /companies/search?country=CZ&company_number=45274649 |
| VAT number | The register data holds no VAT number for this identifier. |
A few live companies fail the check. A 9 or 10 digit number is a birth number (a natural person) and is refused. Sole traders are never served.
curl "https://api.prometiam.com/functions/v1/risk-api/companies/search?country=CZ&company_number=45274649" \ -H "Authorization: Bearer YOUR_API_KEY"
Shape notation: N digit · L letter · X digit or letter · C check digit or character · {n} repeat n times.
A valid shape and check digit prove that a number is well-formed, not that a company holds it. Only a lookup in the register answers that.
Register data that the API serves for Czech Republic carries this credit:
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.
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