About this plugin
チェックアウトのインボイス登録番号を国税庁の公開 API でリアルタイム照合。登録の有無を注文に保存。
日本語の説明
このプラグインが向いている方: チェックアウトで収集したインボイス登録番号が 本当に国税庁に登録されているか をその場で確認したい WooCommerce ショップオーナー。
できること:
購入者が登録番号を入力すると、このプラグインが 国税庁の適格請求書発行事業者公表システム Web-API に問い合わせ、登録されているかどうかをリアルタイムで確認します。確認結果（「登録あり」「登録なし」など）は注文に保存されるため、管理画面でいつでも参照できます。
主な機能:
- 国税庁の公開 API で登録番号を照合（チェックアウト時・自動）
- 照合結果を注文メタに保存（管理画面で確認可能）
- 未登録番号でのチェックアウトをブロックする設定（任意）
- 同じ番号を何度も照合しないキャッシュ機能（デフォルト24時間）
事前準備: 国税庁の Web-API を使うには アプリケーション ID（利用申請） が必要です。申請から発行まで 1〜2 か月かかる場合があります。ID がない間はチェックアウトをブロックせず通常通り動作します。
このプラグインは入力欄を追加しません。 先に Kazuki Qualified Invoice Number for WooCommerce をインストールして入力欄を追加してください。
関連プラグイン:
- Kazuki Qualified Invoice Number for WooCommerce — チェックアウトに登録番号入力欄を追加
- Kazuki Accounting Export for WooCommerce — 注文を弥生・freee・マネーフォワード形式でエクスポート
Who this is for: WooCommerce shops that already collect 適格請求書発行事業者登録番号 (T + 13 digits) at checkout and want to know whether the number is really registered with Japan’s tax office—not just whether it looks like the right format.
What it does in plain terms:
When a customer enters a registration number, this plugin asks the National Tax Agency (NTA) public register whether that number is active. The result is saved on the order so you can see “valid” or “not found” in the admin. You can optionally block checkout if the number is not valid on the register.
This plugin does not add a checkout field. Install Kazuki Qualified Invoice Number for WooCommerce first (or use your own field that saves the same order data).
Typical workflow:
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Install the registration number field plugin and enable the checkout field.
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Apply for a free Application ID on the NTA website (often takes 1–2 months to arrive).
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WooCommerce → Settings → 登録番号照合 — paste the Application ID.
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Customer enters a number at checkout → plugin checks the NTA register automatically.
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You see the verification result on the order (registered name when available).
What you need to know (no tax expertise required):
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Format vs. real registration — another plugin (or your theme) should check that the value looks like T + 13 digits. This plugin only checks the official public list.
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Without an Application ID — verification is skipped; checkout is not blocked.
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Caching — the same number is not queried on every page load (default: 24 hours).
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Works with classic checkout and WooCommerce Checkout Block fields from the Kazuki registration number plugin.
Works well with:
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Kazuki Qualified Invoice Number for WooCommerce — checkout field and format check
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Kazuki Accounting Export for WooCommerce — journal export for Yayoi; registration number in memo
Enjoying this plugin? org would mean a lot to us — thank you.
External services
This plugin connects to the National Tax Agency (NTA) Qualified Invoice Issuer Publication System Web-API to verify whether a registration number is valid on the public register.
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Service: NTA Invoice Issuer Publication System Web-API (number lookup endpoint).
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What is sent: Your NTA Application ID, the registration number to look up (T + 13 digits), and standard HTTP request metadata. Sent only when a customer enters a registration number at checkout (or when an order is saved with a number), and when the store owner has configured an Application ID.
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When: During WooCommerce checkout validation and when saving order verification metadata. Responses may be cached in the WordPress database for a configurable period (default 24 hours).
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Terms of service: Web-API terms of use, NTA publication site terms.
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Privacy policy: NTA personal information protection policy.
This service is provided by the National Tax Agency of Japan. Verification results are based on public register data; the NTA does not guarantee third-party services built on this API.