Kazuki Invoice Registration Verify for WooCommerce

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:

1. Install the registration number field plugin and enable the checkout field.

2. Apply for a free Application ID on the NTA website (often takes 1–2 months to arrive).

3. WooCommerce → Settings → 登録番号照合 — paste the Application ID.

4. Customer enters a number at checkout → plugin checks the NTA register automatically.

5. You see the verification result on the order (registered name when available).

What you need to know (no tax expertise required):

• 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.

• Without an Application ID — verification is skipped; checkout is not blocked.

• Caching — the same number is not queried on every page load (default: 24 hours).

• Works with classic checkout and WooCommerce Checkout Block fields from the Kazuki registration number plugin.

Works well with:

• Kazuki Qualified Invoice Number for WooCommerce — checkout field and format check

• Kazuki Accounting Export for WooCommerce — journal export for Yayoi; registration number in memo

Enjoying this plugin? If it helps your shop, a review on WordPress.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.

• Service: NTA Invoice Issuer Publication System Web-API (number lookup endpoint).

• 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.

• 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).

• Terms of service: Web-API terms of use, NTA publication site terms.

• 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.