Kazuki Qualified Invoice Number for WooCommerce

Who this is for: WooCommerce shops in Japan that sell to registered businesses and must record the buyer’s 適格請求書発行事業者登録番号 on orders and invoices.

What it does in plain terms:

When a company buys from your site, they often need their registration number on the transaction record. This plugin adds a field at checkout so customers can enter it. The number is saved on the order, shown in the admin order screen, and can appear in order emails.

Typical workflow:

1. Install and enable the plugin.
2. WooCommerce → Settings → インボイス登録番号 — choose optional or required.
3. Customer enters their number at checkout (classic or Checkout Block).
4. You see the number on the order when preparing invoices or bookkeeping.

Features:

• Checks that the value looks valid (T + 13 digits) before the order is placed
• Works with WooCommerce Checkout Block
• Optional: show the number in customer order emails

This plugin does not check whether the number is really registered with the tax office. Use the NTA public site for manual checks. A companion plugin for automatic checkout verification is pending WordPress.org review (not published yet).

Works well with:

• Kazuki Accounting Export for WooCommerce — copies the registration number into Yayoi journal export

Enjoying this plugin? If it helps your shop, a review on WordPress.org would mean a lot to us — thank you.