Japan's business registers are fragmented.
We make them easy to work with.

Daichodo is the ledger API for Japanese regulatory registers. Company data and invoice registration live in separate government registers that do not reference each other, in Japanese, in formats built for people rather than programs. Daichodo holds them, keys them to one entity, and answers by number — including whether a registration was valid on the date of an invoice.

Get an API key Check a number

Free tier, no card. Sole traders included. Keys are issued instantly.

registry_events Diffs retrieved every business day

T1180301018771	トヨタ自動車株式会社	Active
T7010401022916	日本電気株式会社	Active
T8010001034014	(example) Sample Shoji Co., Ltd.	Active
T9010001008669	国際航業株式会社	Active
T5010001000010	ニチバン株式会社	Active

Lapses and revocations are kept as history. Every diff we have ever retrieved is still here, so a record can be asked about as at a past date rather than only as at today.The changing row is illustrative and uses an unassigned number. The others are taken from the published register.

5.8M

corporations (法人番号)

5.4M

qualified invoice issuers

50.4%

of invoice issuers are sole traders

Daily

every business day's diff, kept

Who it is for

KYB and identity platforms

Verify a Japanese business and keep dated evidence you can still defend six months later.

Marketplaces and platforms

Onboard a Japanese seller once, then hear about it when their invoice registration lapses.

Tax and billing engines

A qualified invoice is deductible only if the issuer was registered on the invoice date.

Agencies, small businesses, sole traders and individual developers use the same free tier and the same endpoints. No company required, no sales call.

What you can do with it

Nothing rolls off

The NTA's own diff files are withdrawn after 40 business days. Every one published since we started is kept here, so the record does not thin out as that window moves. Date-range search across the change log is Premium, and Premium is not open yet.

Check a past date

Was this registration valid on the date of the invoice? Answered from the change log, sole traders included.

Served from our own copy

A maintenance window or a rate limit on the government side is not an outage here, and there is no application ID of yours to manage.

One entity, both registers

Company records and invoice registration are keyed to the same entity, so you are not matching them up yourself.

Built for name matching

Field names, errors, docs and SDKs are English; the register data stays Japanese, exactly as published — no romanised company names. Gaiji records are flagged and the NTA's image ids kept, because that is the raw material cross-register name matching needs and it cannot be re-fetched later. The matching itself is what we are building next. It is not available today.

What is covered

Two National Tax Agency registers, retrieved every business day and kept. Two more are planned.

Corporate numbers (法人番号)Live
Qualified invoice issuers (適格請求書発行事業者)Live
Closure, succession and readings (法人番号)Planned
官報 legal noticesPlanned

See what each register contains

Try it

Format and check-digit validation needs no API key and stays free at every tier. It proves the number is well-formed, not that it is registered.

npm install @daichodo/validate

import { isValid } from '@daichodo/validate';
isValid('T8000000000001'); // true

Looking a number up against the register needs a key. Test keys hit the same endpoints with test data, so you can wire the integration before you pay for anything.

curl https://api.daichodo.com/v1/invoice-issuers/T8000000000001 \
  -H "Authorization: Bearer dc_test_..."

What to read next

The guides are about the problem rather than the API: the diff window that expires, the check digit that proves less than it looks, and why Japanese company names are hard to match.

How to validate a Japanese invoice registration numberCheck a Japanese qualified invoice issuer registration number properly: format, check digit, whether it is registered, and whether it was valid on the invoice date.Working with Japan’s corporate number (法人番号) APIWhat the NTA publishes, what its Web-API does and does not give you, and when hosting your own copy stops being worth it.Why matching Japanese company names is hardGaiji, variant characters, width, and where 株式会社 sits. What actually goes wrong when matching Japanese company names, and why string equality fails.

The documentation is the reference, from your first API key to point-in-time validity and change-detection webhooks.

QuickstartFrom nothing to your first verified registration number.LookupLook up a number, and ask whether it was valid on a given date.Validating numbersCheck-digit validation. Free, unmetered, and open source.Change-detection webhooksGet told the moment a number you watch changes, with a verifiable signature.