Shape, check digit, accepted and refused examples and the API call for Unified business number in Taiwan. 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 | GCIS (Ministry of Economic Affairs), Ministry of Finance |
| Shape | N{7} C |
| Check digit | Advisory. 8 digits. Weights 1,2,1,2,1,2,4,1, each product taken as tens digit plus units digit; the total should divide by 5 (10 before the 2023-24 change; a 7th digit of 7 may count as 0 or 1). Advisory: a mismatch is a warning. |
| Worked example (accepted) | 22099131 |
| Normalised form | 22099131 |
| Also accepted as input | TW22099131 |
| A one-character slip | 22099132 is accepted with a warning |
| Regex (normalised form) | ^[0-9]{8}$ |
| API call | GET /companies/search?country=TW&company_number=22099131 |
| VAT number | the 8-digit UBN, where the company is in the Ministry of Finance tax file — published or confirmed by the register |
A few old dissolved numbers fail both rules. Seven digits are padded with a zero. Companies and Taiwan branches of foreign companies only; names are in Chinese.
curl "https://api.prometiam.com/functions/v1/risk-api/companies/search?country=TW&company_number=22099131" \ -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 Taiwan carries this credit:
Contains data from the Ministry of Economic Affairs, Department of Commerce (GCIS open data platform) and International Trade Administration (English names), and the Ministry of Finance, Fiscal Information Agency (business tax registration data), Republic of China (Taiwan), released under the Open Government Data License v1.0 (https://data.gov.tw/license). Adapted by Prometiam, not a certified register extract.
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