Japan Corporate Number check
Check that a Japan Corporate Number is well formed and its check digit is right, before you pay or onboard a supplier. Format only
Example: 1180301018771 (Toyota Motor Corporation). No account needed: 10 lookups a day per network, shared with the keyless API.
What this check tells you
Format only
We check the structure and the check digit published by the issuing authority, offline. That catches typos and made-up numbers. It does not show that the business exists, is registered or is active, so a well-formed number gets review, never pass. To confirm registration, use the official lookup: National Tax Agency Corporate Number Publication Site.
Japan ID formats we check
| ID type | Level | Check digit | API endpoint | Official lookup |
|---|---|---|---|---|
| CN Corporate Number (法人番号), also the base of the invoice number “T…” | Format only | National Tax Agency mod 9 (leading check digit) | GET /v1/jp/cn/{id} | National Tax Agency Corporate Number Publication Site |
From code
Same key and quota as every other country. A well-formed request costs one lookup; a source that does not answer returns HTTP 503 and is not counted.
curl "https://taxid.halpii.com/v1/jp/cn/1180301018771" \
-H "Authorization: Bearer $KEY"Get a no-cost API key (100 lookups a day) or read the API docs.
Questions
Does a valid Corporate Number mean the company exists?
No. This is a format check: it confirms the structure and check digit, not that the business exists or is active. Confirm registration with National Tax Agency Corporate Number Publication Site.
Where does the data come from?
No registry is queried. The rules come from the issuing authority's published format and check-digit algorithm (National Tax Agency mod 9 (leading check digit)).
Can I check Corporate Numbers from code or in bulk?
Yes. The same check is available over the REST API (GET /v1/jp/cn/{id}) and the MCP server, with the same key as every other country. See the API docs.
Is this service affiliated with the Japan tax authority?
No. HALPII Tax ID is an independent service run by HALPII S.A.C. (Lima, Peru). Results are informational, not legal or tax advice.
Other countries in Asia-Pacific
All countries and verification levels
Last updated 2026-11-14. An independent service run by HALPII S.A.C. (Lima, Peru), not affiliated with or endorsed by any Japan authority.