Strengthening Japan Coverage with the Universal Postal Union’s POST*CODE® Database

Licensed Japanese addressing data to ensure richer, more precise, and localized validation in kanji, kana, and romaji.

One of Addresszen’s missions is to provide truly localized address data that reflects the nuances of each market we serve. We enrich datasets down to the property level, capturing specific postal, administrative and linguistic conventions that vary from region to region. We license Japanese address data from the POST*CODE® DataBase of the Universal Postal Union (UPU), bringing even richer, more accurate postal data into our address verification service.

The Universal Postal Union

The UPU is a specialized United Nations agency that has served as the central hub for postal cooperation and development since 1874. Over the years, they have collected authoritative postal information directly from member postal operators around the world.  

Why We Chose UPU Addressing Data

Our localized approach requires the most granular, official data available. In Japan, postal codes are tied to local delivery offices, community boundaries, and even building names, so having authoritative data matters. Integrating UPU addressing data delivers:

Authority

Data originates from Japan Post and GSI’s geospatial information, ensuring postal code ranges and related metadata are accurate. We achieve broad coverage, from major cities to small towns and islands.

Standardization
The database adheres to UPU standards for formatting, character sets and transliterations. Many of our customers have global footprints, so being able to output Japanese addresses in kanji, hiragana or romaji is essential for both domestic and international use.

Regular Updates

Postal codes evolve with new developments and administrative changes. Certain rural prefectures have unique postal code allocations that are updated more rapidly through the UPU pipeline than through third-party sources alone.

How We Use the Japan Dataset

Japan’s addresses use a mix of writing systems, primarily Kanji (complex characters adapted from Chinese) for place names and street information, with Kana (phonetic alphabet) and Romaji (Latin letters) for building names or transliterations. To ensure we deliver the most accurate and user-friendly results, our address verification now includes:

Language-Aware Validation: We return each address in the same language as that the user entered. If an input matches more than one script, the Kanji, Hiragana and Latin versions are displayed as separate find results.

Automatic Handling of Kana and Romaji: Inputs in Hiragana, Katakana or Romaji are converted and normalized using Hepburn romanization rules. This means you can enter “Shinjuku-ku” in Romaji or “しんじゅく区” in Hiragana, our address autocomplete will recognize the same destination.

Multilingual Outputs: Administrative names such as prefectures, cities, wards, towns and sub-districts are provided in their native script and, where a Latin version exists, in Latin letters, for example, “Tokyu Plaza”.

Correct Address Formatting: Japanese addresses do not contain spaces between components, except for a single space after the postal code (e.g., “〒150-0001 東京都渋谷区神宮前”). We preserve this convention by default.

What this Means for AddressZen Customers

In Japan, most people type addresses using a standard romaji keyboard on their PC or mobile device, which converts into Hiragana and then suggests Kanji. On smartphones, many use flick input, where you tap a Hiragana character and swipe to pick the one you want. A smaller number still prefer a dedicated Kana keyboard. By supporting all these common input methods, our integration can recognize and validate any address your customers or teams enter.  

With UPU’s Japan database on board, this partnership empowers your business with smoother shipping operations, reduced error handling and complete confidence that every Japanese address in your system is verified and enriched to the highest level of detail.

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