Shape, check digit, accepted and refused examples and the API call for NIP / REGON in Poland. 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 | Krajowa Administracja Skarbowa (KAS) |
| Shape | N{9} C |
| Check digit | Enforced. Weights 6,5,7,2,3,4,5,6,7 over the first 9 digits; the sum mod 11 is the check digit. A remainder of 10 is never issued. |
| Worked example (accepted) | 7740001454 |
| Normalised form | 7740001454 |
| Also accepted as input | 774-000-14-54 |
| A one-character slip | 7740001455 is refused |
| Regex (normalised form) | ^[0-9]{10}$ |
| API call | GET /companies/search?country=PL&nip=7740001454 |
| VAT number | PL + NIP — built from the identifier by rule; the registration is not confirmed |
The NIP is the tax number. The KRS register number (10 digits, zero-padded, taken by company_number) has no check digit and is not validated here.
curl "https://api.prometiam.com/functions/v1/risk-api/companies/search?country=PL&nip=7740001454" \ -H "Authorization: Bearer YOUR_API_KEY"
| Field | Value |
|---|---|
| Register | GUS (REGON) |
| Shape | N{8} C | N{13} C |
| Check digit | Enforced. REGON-9: weights 8,9,2,3,4,5,6,7, sum mod 11 (10 reads as 0). REGON-14 repeats that on its first 9 digits and adds a second check over all 13 (weights 2,4,8,5,0,9,7,3,6,1,2,4,8). |
| Worked example (accepted) | 610188201 |
| Normalised form | 610188201 |
| A one-character slip | 610188202 is refused |
| Regex (normalised form) | ^([0-9]{9}|[0-9]{14})$ |
| API call | GET /companies/search?country=PL®on=610188201 |
| VAT number | The register data holds no VAT number for this identifier. |
REGON-9 identifies the entity, REGON-14 a local unit of it.
curl "https://api.prometiam.com/functions/v1/risk-api/companies/search?country=PL®on=610188201" \ -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.
Start your 14-day free trial · API documentation
The free trial lasts 14 days and includes 500 credits. A card is required and nothing is charged during the trial; it then continues as Starter (EUR 9.99/month) unless you cancel.