# jp-corporate-number

> What does Japan's National Tax Agency publish for this corporate number, and which corporate numbers match this organization name? Hosted MCP and HTTP: no install. Name, location, kind, assignment date and closure date as recorded (with the recorded cause code and successor number), optional change history, and corporate number candidates for a name (all candidates, never collapsed to one), with the NTA Web-API source statement, retrieval time and a freshness receipt. Free. Not an official government result.

Data source: National Tax Agency of Japan (NTA) - Corporate Number System Web-API (Ver.4), https://www.houjin-bangou.nta.go.jp/webapi/ (specification: https://www.houjin-bangou.nta.go.jp/pc/webapi/images/k-web-api-kinou-gaiyo.pdf , https://www.houjin-bangou.nta.go.jp/pc/webapi/images/k-web-api-kinou-ver4.pdf; Web-API terms: https://www.houjin-bangou.nta.go.jp/webapi/riyokiyaku.html; site terms: https://www.houjin-bangou.nta.go.jp/riyokiyaku/). Required source statement: このサービスは、国税庁法人番号システムWeb-API機能を利用して取得した情報をもとに作成しているが、サービスの内容は国税庁によって保証されたものではない (English: This service is built on information obtained through the Web-API function of the National Tax Agency Corporate Number System, but its content is not guaranteed by the National Tax Agency.) Source notice: 国税庁法人番号公表サイト（国税庁）（https://www.houjin-bangou.nta.go.jp/）をもとに MK Career Planning 作成 Each answer adds the retrieval time. This answer was produced by MK Career Planning by processing information published by the National Tax Agency. It is not an official result of the National Tax Agency or the Government of Japan.
Information from the National Tax Agency (NTA) Corporate Number System Web-API, relayed and processed by MK Career Planning. Its content is not guaranteed by the NTA, it is not an official result of the NTA or the Government of Japan, and it is not a decision on whether to trade with, lend to or contract with any party. A closure is shown as recorded by the NTA; no reason is inferred.
nta_corporate_number_lookup: listed (record_state closure_recorded only when the record states a closure date), not_found_in_checked_records (the NTA answered with no record for a number whose check digit is valid), or unknown.
unknown_reason upstream_not_configured, rate_capped (this service caps its own calls to the NTA; ask again later), too_many_results, upstream_access_restricted, upstream_app_id_rejected, upstream_error or record_withdrawn never means not found.
Closures: close_date, the close_cause code as recorded with its official NTA label, and successor_corporate_number. No other reason is inferred or added.
nta_corporate_number_search: candidates_found, no_candidates_found or unknown. Every candidate's corporate number is returned (candidate_corporate_numbers); match_basis exact_name or fuzzy_candidate. Neither is an identity match, and the service never chooses one.
status_as_of is the NTA's lastUpdateDate; fetched_at is when this service retrieved it. Answers are fetched from the NTA on demand and cached for up to 1 day.

## Privacy at a glance

- No account, no email, no API key. Free tools need nothing but the call.
- Free tools: we do not store your inputs (for example the number or name you looked up) in our database (except as noted below), and request logging is turned off for this service, so your inputs and IP address are not kept in a request log. Usage is counted only as daily totals.
- This server takes no payments.
- This service has its own data notes (for example what it passes to another source or keeps as a hash): see section 1 of the Privacy Policy.
- Details and exceptions (Cloudflare's own processing): https://jp-corporate-number-production.mk-career-planning.workers.dev/privacy

## Connect

- MCP (streamable HTTP): https://jp-corporate-number-production.mk-career-planning.workers.dev/mcp
- OpenAPI: https://jp-corporate-number-production.mk-career-planning.workers.dev/openapi.json
- x402 discovery: https://jp-corporate-number-production.mk-career-planning.workers.dev/.well-known/x402

## Quickstart

- Developer quickstart (MCP client configs, free curl/TypeScript calls, how to read status, unknown_reason, closures and the required NTA source statement): https://jp-corporate-number-production.mk-career-planning.workers.dev/quickstart

## Free tools

- catalog: List the tools of this server with prices, data sources, licensing, daily limits and data freshness.
- nta_corporate_number_lookup: What does Japan's National Tax Agency (NTA) publish for this 13-digit corporate number? Returns the name, furigana, English name, kind, location, assignment date and, when the record states it, the closure date with the recorded cause code and successor corporate number (no reason is inferred). Optional change history. Distinguishes not found in the NTA records from could not check. Carries the NTA Web-API source statement. Not an official result.
- nta_corporate_number_search: Which Japanese corporate numbers could this organization name refer to? Searches the National Tax Agency (NTA) Web-API by name (prefix match after the legal form, with the NTA's fuzzy matching), optionally within a prefecture, and returns every candidate with corporate number, name, location and recorded closure date, marked exact_name or fuzzy_candidate. Never picks one for you. Carries the NTA Web-API source statement. Not an official result.
- get_receipt: Re-fetch the stored result of a settled paid call by its receipt_id, for when the response was lost after payment. Free. Unknown or unsettled receipt ids return RECEIPT_NOT_FOUND. Results are kept for 30 days after settlement.
- HTTP: GET https://jp-corporate-number-production.mk-career-planning.workers.dev/v1/corporate-number/lookup, GET https://jp-corporate-number-production.mk-career-planning.workers.dev/v1/corporate-number/search return the same data as the MCP tools. GET https://jp-corporate-number-production.mk-career-planning.workers.dev/v1/receipts/<receipt_id> is get_receipt.

## Payments

This server offers free tools only. It does not request or accept x402 payments.

## Rate limits

- Free calls (free HTTP endpoints under /v1/ and free MCP tools) are limited to 300 requests per 60 seconds per client (a client is keyed by a one-way hash of its IP address and the first 64 characters of its User-Agent; neither is stored. The User-Agent can be set by anyone, so this split is for fairness between clients behind a shared gateway, not a security control). Over the limit, HTTP returns 429 RATE_LIMITED with a Retry-After header and MCP tools return the error RATE_LIMITED. Paid calls are not rate limited.

## Provenance and fetch_status

Responses carry provenance[] (source, upstream_updated_at, retrieved_at, content_sha256, parser_version, fetch_status). fetch_status values:

- found: The upstream document was retrieved and contains the data used for this answer.
- empty: The upstream was retrieved, but it has no item for this query (for example JMA had no bulletin for that area in its feeds, or the municipality is not in the list). The state is unknown: empty does NOT mean 'none in effect'.
- stale: The data was retrieved but is older than the freshness threshold for its kind; treat it with care.
- unavailable: The upstream could not be retrieved, read or used (network error, withdrawn bulletin, paused source, or data not yet loaded).
- unsupported: The query is outside what this source covers (for example a date JMA does not issue warnings for yet, or a period before the source's records).

## Errors

- RECEIPT_NOT_FOUND (get_receipt)
- RATE_LIMITED (free calls over the per-client limit; HTTP 429 with Retry-After; not charged)

## Terms

- Keep the attribution (source_statement_ja, notice_ja with the retrieval date, and the statement that it is processed by MK Career Planning and not an official result) when you pass results on.
- Not a decision on whether to trade with, lend to or contract with any party.

## Privacy and support

- Operator: MK Career Planning
- Terms of Service: https://jp-corporate-number-production.mk-career-planning.workers.dev/terms
- Privacy policy: https://jp-corporate-number-production.mk-career-planning.workers.dev/privacy
- Support (free): https://jp-corporate-number-production.mk-career-planning.workers.dev/support (mk.career.planning@gmail.com)