A Valid Japanese Address Example
A valid Japanese address example runs in the opposite direction from a US or UK address: the postal mark and postal code lead, then the prefecture, then progressively smaller units down to the block and house number — for example "〒150-0001" on the first line, "Tokyo-to" (a prefecture) on the second, and the city, ward and block number on the third. UPU S42 documents Japan as one of the clearest real-world cases where "largest unit first" is the native convention, the reverse of how USPS Publication 28 orders a US address from smallest unit (the street) to largest (the state).
Every Japanese record Fake Addresses generates carries a real postal code and a real prefecture, city or ward, and sub-area name, because a Japanese postal code is not an independently surveyed area the way a UK postcode unit or a US ZIP Code Tabulation Area is: it is itself the prefecture, city and neighbourhood-block join, issued as a single record. The block and house number are synthesised, because no free source reaches that final level of detail, so the last two digits an address ends on are always a clearly labelled placeholder.
A QA engineer testing a Japanese shipping or billing form needs both the reversed field order and the postal code's own three-digit-hyphen-four-digit shape to be correct at the same time. A real Japanese address-input service checks the structure before it checks anything about the content, and Fake Addresses treats getting that structure right as inseparable from getting the underlying place names right.
Japanese Postal Code Format and Examples
Fake Addresses generates a Japanese postal code that is always three digits, a hyphen, then four digits, conventionally preceded by the 〒 postal mark when printed:
| Postal code | Prefecture | City / ward | Full first line |
|---|---|---|---|
| 〒150-0001 | Tokyo-to | Shibuya-ku | 〒150-0001 |
| 〒530-0001 | Osaka-fu | Kita-ku | 〒530-0001 |
| 〒060-0001 | Hokkaido | Sapporo-shi, Chuo-ku | 〒060-0001 |
| 〒460-0001 | Aichi-ken | Nagoya-shi, Naka-ku | 〒460-0001 |
How Japanese Address Format Compares to the United States and the UK
Fake Addresses treats Japan as the clearest reversal in this comparison: the postal code opens a Japanese address instead of closing it, and the field order runs largest unit to smallest instead of smallest to largest:
| Country | Last-line order | Postal-code position |
|---|---|---|
| Japan | Reversed: postal mark and code first, then prefecture, then smaller units | Very first line |
| United States | City, State, ZIP+4 | End of the last line, per USPS Publication 28 |
| United Kingdom | Post town, then postcode on its own line beneath it | Final line, on its own |
Synthetic Test Data Generation for Japanese Test Addresses
Synthetic test data generation for Japan is a genuinely different engineering problem from every other country Fake Addresses covers, because getting the field order backwards is not a minor formatting slip — it produces a string a Japanese address parser will not recognise as an address at all. A QA engineer who only swaps in Japanese place names without reversing the field order has not actually tested the Japanese code path.
Fake Addresses states its Japanese coherence level plainly on the random Japan address generator: the prefecture, city or ward, and postal code are all real and drawn from the same source record, while the block and house number are synthesised because no free source reaches that level of detail. A QA engineer can treat the reversed field order and the underlying place data as two separate things Fake Addresses gets right independently, not one bundled claim.
Every generated Japanese record stays non-deliverable by construction. The block and house number, the one part of the address a real delivery depends on most precisely, are always synthesised rather than drawn from a real registry, so a Japanese test fixture built from this data carries no risk of resolving to somebody's real address even though the postal code and prefecture around it are genuinely real.
Frequently asked questions
Why does a Japanese address start with the postal code?
Japanese address format runs largest unit to smallest, so the postal mark and postal code lead the address, then the prefecture, then progressively smaller units. Fake Addresses follows this reversed order on every generated Japanese record rather than applying a US-style smallest-to-largest structure.
Is the Japanese postal code always seven digits?
Yes, split as three digits, a hyphen, then four digits, for example "〒150-0001". Fake Addresses generates every Japanese postal code against that same fixed shape, distinct from a US five-digit ZIP code or a UK postcode's variable-length letters and digits.
What part of a Fake Addresses Japanese address is synthesised?
The block and house number at the end of the address are synthesised, because no free source reaches that level of detail for Japan. The prefecture, city or ward, and postal code above them are real and drawn from the same underlying record.
Sources
- Universal Postal Union — The Universal Postal Union runs an addressing-solutions programme, including international addressing standards and assistance to member countries whose addresses do not follow a US or UK-style format.
- United States Postal Service — Postal Explorer — USPS Publication 28 defines a "standardized address" as one using official USPS abbreviations, and a "complete address" as one containing everything needed to match the ZIP+4 and City State files.