📬 Japan Postal Code Lookup (7-Digit to Prefecture)

Japanese postal codes (郵便番号, yūbin bangō) are seven digits, usually written as XXX-XXXX. They were introduced nationwide in 1998 to replace the old three-digit system, and they appear on every Japanese address, invoice, and online checkout form.

The first two digits identify a postal district that almost always falls inside one prefecture - for example codes starting with 10–20 belong to Tokyo, 21–25 to Kanagawa, and 90 to Okinawa. Because a few prefixes (such as 63–64, 68 and 81) are shared across neighbouring prefectures, a code alone cannot always name a single prefecture with certainty, but it narrows the options to one to three.

Famous landmarks make the system easy to remember:

This tool validates a 7-digit code, converts full-width (全角) digits such as ０３６ into half-width, adds the standard hyphen, and returns the prefecture (or prefectures) that the prefix belongs to. It also reports the broader region of Japan (Hokkaido, Tohoku, Kanto, and so on) as a secondary hint. For exact town-level lookup, use the official address formatter with the Japan Post search, and pair the result with our postage calculator when you are ready to send something.

The calculator takes a postal code as digits (7 digits, with or without a hyphen).It strips spaces and hyphens, converts any full-width digits, then checks that exactly 7 digits remain.The first two digits are looked up in the prefix–prefecture table below, and the result shows every prefecture that prefix can belong to.

For example, 104-0061 starts with 10, which belongs to Tokyo - this is the Ginza area (銀座).060-0806 starts with 06 and is therefore Hokkaido (Sapporo).The full 47-prefecture mapping is embedded in the tool so every prefix 00–99 is covered, including ambiguous ones.Neighbouring prefectures can even share the same two-digit range - prefix 01 covers both Akita and Aomori, and 38 covers Niigata, Gunma and Nagano - which is exactly why a lookup table beats guesswork.If you need the town-level address behind a code, combine this with our municipality lookup or the prefecture picker.

1. Type a 7-digit postal code, with or without a hyphen (e.g. 1040061 or 104-0061).
2. Full-width digits are converted automatically, so copying from another page works as-is.
3. Click Look Up to see the hyphenated form and the prefecture (or prefectures) matching the prefix.
4. Review the reference table to learn which prefixes belong to which prefecture.
5. Use the town-level official Japan Post search if you need the exact address for a code.

Can one postal code belong to more than one prefecture?

Yes. A few prefixes are shared across neighbouring prefectures - for example 63 is shared by Osaka and Nara, 68 by Shimane and Tottori, and 81 by Fukuoka and Nagasaki. The tool lists every matching prefecture instead of guessing one.

Are Japanese postal codes 7 digits always?

Since 1998 yes. The format is three digits, a hyphen, then four digits (XXX-XXXX). The old three-digit system still appears on some legacy documents but modern codes are always seven digits.

What does the first digit mean?

The first two digits represent a postal district and usually fall inside a single prefecture. The first digit alone is only a rough indicator: 0 covers Hokkaido and Tohoku, 1 the Tokyo area, and 9 mixes Okinawa (90) with the Hokuriku (91–95) and Tohoku (96–99) regions.

How do I write a postal code on an envelope?

Write 〒 followed by the seven digits, e.g. 〒104-0061, on the first line of the address. The address order is postal code, prefecture, city, town, block, building, recipient.

Is full-width input handled?

Yes. Full-width digits (０１２３４５６７８９) are automatically converted to half-width before validation, which is important because Japanese keyboards and mobile IMEs often produce them.

Does this tool cover all 47 prefectures?

Yes - the prefix table embedded in the tool maps every prefix from 00 to 99 to its one to three possible prefectures.

Japanese web forms frequently switch your input to full-width digits automatically, so the first thing this tool does is normalise full-width ０１２３ into half-width 0123.The official Japan Post search is the only authority for the exact town associated with a code, because one 7-digit code can cover several towns and even parts of two municipalities in rural areas.When writing an address on an envelope, the postcode is written first with the 〒 symbol, then the prefecture, city, town, block and building.If you are moving to Japan, knowing your new prefecture’s prefix range helps you instantly recognise where an envelope comes from.Also note that Okinawa's 90- prefix and Hokkaido's 04–09 range are the easiest to remember; from Tokyo the numbers run westwards down to Kyushu, before 91–99 loop back to the Hokuriku and Tohoku regions.For shipping costs after you know the destination, open the postage calculator.