Shape, check digit, accepted and refused examples and the API call for Y-tunnus in Finland. 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 | PRH / YTJ |
| Shape | N{7}-C |
| Check digit | Enforced. Weights 7,9,10,5,8,4,2 over the 7 digits; check = 11 minus the sum mod 11 (0 when the remainder is 0). A remainder of 1 has no check digit, so such a number is never issued. |
| Worked example (accepted) | 0112038-9 |
| Normalised form | 0112038-9 |
| Also accepted as input | 01120389 · 112038-9 |
| A one-character slip | 0112038-8 is refused |
| Regex (normalised form) | ^[0-9]{7}-[0-9]$ |
| API call | GET /companies/search?country=FI&company_number=0112038-9 |
| VAT number | FI + the 8 digits without the hyphen — published or confirmed by the register |
A 6-digit body (a pre-2001 trade-register number) is read with its leading zero restored.
curl "https://api.prometiam.com/functions/v1/risk-api/companies/search?country=FI&company_number=0112038-9" \ -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.
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