---
title: "Normalize a Japanese address (to town level) / 住所の正規化（町域まで）"
method: GET
path: "/v1/addresses/normalize"
---

# Normalize a Japanese address (to town level) / 住所の正規化（町域まで）

`GET /v1/addresses/normalize`

## Request

- Base URL: `https://biz.ossalt.jp`
- URL: `https://biz.ossalt.jp/v1/addresses/normalize`
- Auth: none declared

Split a Japanese address into prefecture, city, town and the rest (block numbers, building), matching Japan Post's address data, and return candidate postal codes. Absorbs full/half-width, spacing, kanji vs. arabic numerals, ヶ/ケ and omitted county names; fills in the prefecture when the city is unique. Does NOT verify block/house numbers and has no coordinates. `level` tells how far the match went: 0 = nothing matched, 1 = prefecture only (see `city_candidates` if the city name is ambiguous), 2 = city matched but not the town (`postal_codes` are city-wide candidates), 3 = town matched. `address` and `municipality_code` are null below level 2. flags: `partial` (level below 3), `ambiguous` (several city or postal code candidates — ask the user or show all). / 住所を都道府県・市区町村・町域・残り（番地・建物名など）に分け、郵便番号の候補を返す（日本郵便のデータにあてはめる）。番地が実在するかの確認と緯度・経度はない。level：0＝わからない、1＝都道府県まで、2＝市区町村まで（町域はわからない）、3＝町域まで。

## Query parameters

- `address` string, required: Japanese address, e.g. 北海道札幌市中央区大通西10丁目1-1 / 住所

## Response `200`

OK

- Answer
  - `result` object, required: The answer / 結果
  - `source` object, required: Source and verification / 出典と照合の状況
  - `as_of` string, required: Reference date in Japan time (YYYY-MM-DD) / 基準日（日本時間）
  - `notes` string[], required: Assumptions such as estimated values / 前提（見込みの値など）
  - `flags` string[], required: `flags` holds machine-readable codes: `estimated` (a value is an estimate, e.g. a future equinox day — tell the user), `unverified` (year not yet checked against Cabinet Office data — tell the user), `assumes_current_era` (a future date written in the current era — tell the user), `outside_era` (the era date given is outside that era), `weekday_mismatch`, `closed` (the company's registry record is closed — tell the user), `excluded_from_search`, `truncated`, `not_found`, `exact_match_only`, `partial`, `ambiguous`, `city_not_found`, `ambiguous_city`.

## Other responses

- `400`: Invalid parameters / 入力の誤り
- `429`: Too many requests / 呼び出しが多すぎます
- `503`: Data unavailable / データを読めない

---

[API](https://skmtc.dev/ossalt/apis/japan-business-tools.md) · [All operations](https://skmtc.dev/ossalt/apis/japan-business-tools/llms.txt) · [OpenAPI document](https://skmtc.dev/ossalt/apis/japan-business-tools/revisions/8bb72a25e175?raw)