Description
Hera Japan Postcode Autofill for WooCommerce fills in the prefecture, city and street of a Japanese address as soon as the customer types the 7-digit postcode. It works on the Checkout block, on the classic checkout and on the address form under My account, for billing and shipping addresses alike.
This is an independent plugin, not affiliated with, endorsed by, or sponsored by WooCommerce or Automattic. WooCommerce is a trademark of Automattic Inc.
When the country of an address is Japan, WooCommerce already asks for the postcode before the prefecture, city and street. A Japanese postcode settles most of what comes after it, so the customer types seven digits and checks the result instead of typing the address out. The plugin works for any store that ships to Japan, whatever language the store itself uses.
Features
- The prefecture (WooCommerce’s state field), the city and the street are filled in as soon as the seventh digit is typed.
- Works with the Checkout block, the classic checkout and My account > Addresses.
- Never overwrites a street the customer typed. When the postcode changes, the prefecture and city follow it, and what the plugin filled in is cleared again if the postcode is no longer complete.
- Accepts full-width digits such as １００－０００１ and rewrites them as 100-0001, the form WooCommerce accepts, as soon as all seven are in.
- Fills in only what the postcode settles. A postcode shared by several towns leaves the street empty, and one shared by two cities leaves the city empty, instead of guessing.
- Covers about 143,000 postcodes, including those Japan Post assigns to a single large business, which fill in the street number as well.
- Acts only on addresses whose country is Japan. Addresses in other countries work as before.
- Tells screen reader users when it has filled in an address.
- Nothing to configure: no settings screen and no database tables.
No external connections
The postcode data ships inside the plugin, in one small file for each set of first three digits. When a customer types a postcode, the browser loads that one file from your own site. Nothing is sent to Japan Post or to any other service, no remote script is loaded, and the plugin stores nothing.
Postcode data
The data comes from the postcode files Japan Post publishes for addresses and for large businesses, in the release of 30 September 2026. Japan Post states that it does not claim copyright on this data and that anyone may redistribute it: https://www.post.japanpost.jp/service/search/zipcode/download/utf-readme.html. Plugin updates bring newer data, and the changelog names the release each version carries.
Documentation
The user guide is at herapress.com/docs.
Support
Use the support forum on this plugin’s WordPress.org page. Please say which postcode you typed, whether your store uses the Checkout block or the classic checkout, and which WordPress and WooCommerce versions it runs.
Screenshots
Installation
- Upload the
hera-japan-postcode-autofill-for-woocommercefolder to/wp-content/plugins/, or upload the zip via Plugins > Add Plugin > Upload Plugin (older WordPress versions call the menu item Add New Plugin). - Activate the plugin through the “Plugins” screen. WooCommerce must be installed and active.
- There is nothing to set up. On the checkout, choose Japan as the country and type a postcode.
FAQ
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Does it work with the Checkout block?
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Yes. It works with the Checkout block, with the classic checkout made by the
[woocommerce_checkout]shortcode, and with the address form under My account > Addresses. -
Does it send my customers’ data anywhere?
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No. The postcode data is part of the plugin and is loaded from your own site. The plugin makes no external requests and stores nothing.
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My store is not in Japan. Can I use it?
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Yes. The plugin acts whenever the country of an address is Japan, so any store that ships to Japan can use it. Addresses in other countries are left to WooCommerce as before.
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Why is the address filled in in Japanese?
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The plugin fills in Japan Post’s data, and Japan Post publishes addresses in Japanese.
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Why did the city or the street stay empty?
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Some postcodes do not settle the whole address. One postcode can be shared by two neighbouring cities, or by several towns in the same city. The plugin then fills in only the part that is certain and leaves the rest for the customer to type.
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Why did the prefecture stay empty?
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The prefecture is set in WooCommerce’s state field, by its WooCommerce code (JP01 to JP47). If the store has changed that field so it no longer lists the Japanese prefectures, the plugin leaves it alone.
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A postcode is not recognized. Why?
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Japan Post adds and retires postcodes every month. Each plugin version carries the data of one Japan Post release, named in the changelog, so update the plugin to get newer data. An unknown postcode leaves the address fields for the customer to fill in.
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What happens when I delete the plugin?
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The plugin stores nothing in your database, so there is nothing to remove.
Reviews
There are no reviews for this plugin.
Contributors & Developers
“Hera Japan Postcode Autofill for WooCommerce” is open source software. The following people have contributed to this plugin.
Contributors
Translate “Hera Japan Postcode Autofill for WooCommerce” into your language.
Interested in development?
Browse the code, check out the SVN repository, or subscribe to the development log by RSS.
Changelog
1.0.0
- Initial release, with Japan Post’s postcode data of 30 September 2026.