Japan company data API: look up and validate a corporate number

A customer types a Japanese corporate number, a T invoice number or the first letters of a name in Japanese or romaji; your form fills in the legal name, kind, status and registered address from the National Tax Agency register. One key, and the same response shape as every other country the API covers.

What you get, and what you do not

Company records from the National Tax Agency corporate number publication site: name, corporate number, address, status and kind, with the kana reading and a romanised name where the register has a reading. Only joint-stock companies (kabushiki kaisha), limited companies (yugen kaisha), general partnership companies (gomei kaisha), limited partnership companies (goshi kaisha), godo kaisha and registered foreign companies are served; national and local government bodies, associations and other corporations are never served. Status is only active, deregistered or merged: the register has no liquidation or insolvency state and there are no insolvency notices. No founding date, activity code, share capital, VAT number or officers, and no registry-compliance signal. Register-change events (name, status, kind and address changes, dated when first seen in the register data, none before the first load in October 2026) and company monitoring are available.

That is the thin record a Japanese onboarding form, an invoice check or a CRM row needs. If you need directors, capital, industry codes, founding dates or insolvency notices for Japan, this is not the API for it. To learn what the register is, start with What is the Japanese corporate number? (also in Japanese).

What the Japanese record gives your product

• Exact match on the corporate number. company_number=1180301018771 with country=JP. Full-width digits, hyphens and a leading T are accepted. The check digit is strict: a value that fails it, or that is 12 digits, is a 400 validation error.
• Autocomplete by name, in Japanese or romaji. ?name= takes Japanese names and romaji; the romanised form is derived from the official kana reading, so it finds corporations that have one. Each call is one request.
• The fields a form needs. The name; the kind; the status; the address with the postal code and city, and the prefecture in region in English.
• A plain status. status is active, deregistered or merged; for a merged company the successor's corporate number is in registry_details.successor_number.
• One schema for every country. The same response shape as the other countries the API covers, selected with country=JP.

• company_number: The 13-digit corporate number: 1180301018771.
• company_name: The name in Japanese as registered.
• legal_form: The kind of corporation (kabushiki kaisha, godo kaisha and so on).
• status: active, deregistered or merged.
• address, postal_code, city, region: The registered address in Japanese; region is the prefecture in English.
• registry_details: The katakana reading (furigana), the romanised name, the English name and English address where registered, and the successor number of a merged company.

An abridged answer for Toyota Motor (illustrative; the real object has the full standard company fields):

Validate before you call

The check is strict, so a form can reject a mistyped number before it costs a call. The identifier validator runs the same arithmetic in the browser:

A passing check says the number is well formed, never that the corporation exists or is still listed. That is what the lookup is for.

Two calls and a list

The search returns the record's id; pass it to the detail endpoint, GET /companies/ followed by the id.

What Japan does not carry

• Officers and shareholders. Not part of the Japanese record.
• Founding date, activity code and share capital. The register publishes none.
• A VAT number. The qualified invoice (T) registration is not in the register data, so none is derived.
• Liquidation and insolvency. The register has no such state, so a company in liquidation is not marked, and Japan is not one of the twelve insolvency markets: there are no insolvency notices.
• Other corporations. Government bodies, associations and other corporations are never served, and neither are individuals.
• A registry-compliance signal. Not served for Japan.

FAQ

How do I look up a Japanese company by corporate number from an API?
Call GET /companies/search?company_number=1180301018771&country=JP. A leading T and full-width digits are accepted. The check digit is strict: a value that fails it, or has only 12 digits, is a 400 validation error.

Can I search by the T invoice number?
Yes. For a corporation the T number is T followed by the corporate number, and a search reads it as the corporate number. The invoice registration itself is not in the register data, so the record has no VAT number.

Can I search in romaji?
Yes, for corporations whose register entry has a katakana reading: the romanised name is derived from it. Corporations without a reading are found by their Japanese name.

Which Japanese entities are covered?
Kabushiki kaisha, yugen kaisha, gomei kaisha, goshi kaisha, godo kaisha and registered foreign companies. Government bodies, associations and other corporations are never served.

Does the record show liquidation or bankruptcy?
No. Status is active, deregistered or merged; the register has no liquidation or insolvency state.

Does it include officers, capital or industry codes?
No. The Japanese record is company-level: name, number, address, status and kind.

How fresh is the data?
The register is read each weekday.

Is there a way to try it before signing up?
Yes: the free corporate number lookup runs the same call with a shared key.

Does it have register-change events and monitoring?
Yes. Register-change events (name, status, kind and address changes, dated when first seen in the register data, none before the first load in October 2026) and company monitoring are available.

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Official source: Corporate Number Publication Site (National Tax Agency).

Source: National Tax Agency Corporate Number Publication Site (https://www.houjin-bangou.nta.go.jp/). Edited and processed by Prometiam; not a product of the National Tax Agency or the State. 出典：国税庁法人番号公表サイト（https://www.houjin-bangou.nta.go.jp/）。Prometiamが編集・加工して作成（国税庁が作成した情報ではありません）。