On the question of which address to use, Japan’s address law is compulsory for the government and voluntary for everybody else. Article 6 of the Act on Residential Indication, Act No. 119 of 1962, tells organs of the state and local government that they must use the new-style address in the basic resident register, the electoral roll, the corporate register and other public registers. In the same article it tells private persons only that they shall endeavour to use it.
That split is why a Japanese address can look like two different systems at once, and it is the right place to start when you are trying to write one. Below: what the Act permits, what the Act requires, and what a seven-digit postcode lets you leave out, taken from the Act itself and from Japan Post’s postcode and barcode manual.
Article 6 binds the registers and asks everyone else to try
The first paragraph of Article 6 is addressed to anyone at all. From the date stated in the municipality’s public notice, anyone indicating a residence in the notified area shall endeavour to use the block symbol and house number, or the road name and house number, assigned under Article 3. The verb is the endeavour form, not the duty form.
The second paragraph changes the verb. Organs of the state and of local government, when indicating a residence in the basic resident register, the electoral roll, the corporate register or other public registers, must use those same assigned items from that date, except where another law or ordinance specially provides otherwise. Three registers are named in the Act and the clause then extends to other public registers.
So the hard obligation in Article 6 sits on official paperwork, and the soft one sits on the citizen. The Act never makes the older parcel-number style unlawful for private use; Article 6 only stops the state from using it in the registers once a new indication has been notified.
The Act permits exactly two methods, and names both
Article 2 covers addresses in built-up areas — a dwelling or temporary abode, or the site of an office, a business establishment or a similar facility — and it lists the methods in two numbered items, with no third.
The first is the block system. A municipality takes a town or aza area and divides it with roads, railways or tramway lines, other permanent facilities, or rivers, waterways and the like. Each divided piece is a block, each block gets a block symbol, and each building or other structure inside the block gets a house number for the purpose of residential indication. The second is the road system, which uses the name of a road inside the municipality together with a house number given to each building or other structure that adjoins the road or has a passage leading to it.
The two definitions divide space differently. The block system numbers an enclosed piece of ground; the road system numbers a line and the things that touch it. Both are in force, and Article 3 makes the choice between them a decision of the municipal assembly for each built-up area it defines.
Both methods sit behind a stack of names the Act requires first
Before either method is reached, Article 2 requires the indication to be prefixed with the names of the prefecture, the county, the city — which the Act states includes a special ward — the ward, and the town or village. The Act defines the ward narrowly: it means a ward under Article 252-20 of the Local Autonomy Act and a general ward under Article 252-20-2 of the same Act, which is to say the administrative wards of designated cities rather than Tokyo’s special wards.
This is the part of a Japanese address that runs largest to smallest and never changes order. The method chosen under Article 2 only governs what comes after it.
A seven-digit postcode lets you drop everything down to the city
Japan Post’s postcode and barcode manual states the omission rule directly. Where the seven-digit postcode is written correctly, the address may omit everything up to and including the city, ward, town or village name. It also states the limit: the writer should confirm the postcode is correct, and everything from the town area downwards must still be written.
| Postcode | Full address as printed | Permitted short form |
|---|---|---|
| 100-0013 | Tokyo, Chiyoda City, Kasumigaseki 1-chome 3-2 | 100-0013 Kasumigaseki 1-chome 3-2 |
| 790-0066 | Ehime Prefecture, Matsuyama City, Miyatamachi 8-5 | 790-0066 Miyatamachi 8-5 |
| 333-0823 | Saitama Prefecture, Kawaguchi City, Oaza Ishigami 978 | 333-0823 Ishigami 978 |
| 966-0049 | Fukushima Prefecture, Kitakata City, Aza Nagaomote 3026-1 | 966-0049 Nagaomote 3026-1 |
| 038-3802 | Aomori Prefecture, Minamitsugaru County, Fujisaki Town, Oaza Fujisaki Aza (a further aza name) 8-2 | 038-3802 Fujisaki Aza (that same aza name) 8-2 |
The first two rows are the ordinary case: the postcode absorbs the prefecture and the city, and the town area survives. The last three rows are the exception that makes the rule one to read twice.
The oaza and aza prefixes drop out, except when aza follows oaza
Where a town-area name is preceded by the characters for oaza or aza, Japan Post states that the omission may run through those characters as well. That is the third and fourth rows of the table: Oaza Ishigami shortens to Ishigami, and Aza Nagaomote shortens to Nagaomote.
The exception is the fifth row. Where a town-area name prefixed with oaza is itself followed by the characters for aza, that second aza cannot be omitted. Japan Post’s own example is the Aomori address under postcode 038-3802, where the town area Fujisaki is prefixed with oaza and followed by a further aza name: the omission runs as far as the oaza and stops there, so the aza and the name after it both stay. One of the two prefixes goes and the other stays, in the same address.
Japan Post runs a telephone service for postcode queries through its customer service consultation centre, and the manual gives its hours as 8:00 to 21:00 every day. The same page notes that the postcode search and download services are published on the company’s website.
The occupier of the building has to display the house number, not the city
Article 8 splits the signage in two. The municipality must put up a display board in a conspicuous place in the notified area, carrying the name of the town or aza inside that area together with the block symbol or the road name. The owner, manager or occupier of a building or other structure in the area must display the house number in a conspicuous place, in the manner prescribed by municipal ordinance.
So the plate naming the district is the municipality’s duty and the plate carrying the number is the occupier’s, and the detail of the second one is left to local ordinance rather than fixed nationally. Article 12 gives the Minister for Internal Affairs and Communications power to set the technical standards for implementation.
Fifty voters can force a public hearing within 30 days
Where creating or abolishing a town or aza area, or altering its boundaries or its name, is needed to implement residential indication, Article 5-2 requires the mayor to publish the draft before taking it to the assembly. People with a residence in the affected area who hold the right to vote in municipal assembly and mayoral elections may then object, by a request for amendment carrying the joint signatures of 50 or more of them, with reasons attached, up to the day on which 30 days have passed since that publication.
The rest of the article is built around that window. The mayor may not submit the bill to the assembly until the period has run. If a request for amendment is made, the mayor must immediately make its substance public, and must attach the request to the bill when it goes to the assembly. The assembly may not vote on such a bill until it has held a public hearing and taken the views of people resident in the area, and it remains free to amend the bill rather than pass it as drafted.
Article 5 governs the names themselves, and only where its first paragraph has had an area redrawn to suit the block system. The new town or aza name is then to be based on the previous name as far as that is possible, and where it is not, it is to be made as easy to read and as simple as possible.
Every notified area has a register, and it must be shown on request
Article 9 requires the municipality to keep a residential indication register for each area covered by an Article 3 notice, and requires it to allow an interested party to inspect that register or a copy of it when one asks. Article 9-2 adds a duty of preservation: where a town or aza name of historical standing has been changed by the implementation of residential indication, the municipality shall endeavour to pass the name on, by setting up markers, collecting materials and taking other necessary measures.
Article 7 removes the cost of the change from the person affected. For applications to alter the residence entries in public registers or notarial documents as a consequence of implementation, or of the setting, alteration or abolition of a block symbol, road name or house number, the fees and other charges that law would otherwise place on the applicant are not collected.
Since 1 January 2024 new areas appear on a ministry page, not in the gazette
Article 3 requires the municipality to report a new residential indication to the prefectural governor, and the ministry used to carry that report into the official gazette so the change was known nationally. The Ministry of Internal Affairs and Communications states that it reviewed the method and stopped using the gazette: for indications newly implemented on or after 1 January 2024, it publishes the content of the municipality’s report on its own website instead.
The ministry’s page lists the batches by fiscal year of publication — the 2025 fiscal year batch covering implementations between 1 January and 31 December 2024, an additional posting for that same batch, and the 2026 fiscal year batch covering 1 January to 31 December 2025. Anyone tracking a renamed district from outside Japan therefore has one web page to read and no gazette to search.
Sources Checked
Ministry of Internal Affairs and Communications, e-Gov law database — Act on Residential Indication, Act No. 119 of 1962
Confirmed the Article 1 statement of purpose; that Article 2 requires the names of the prefecture, county, city including a special ward, ward and town or village to be prefixed and then permits two methods only, the block system and the road system, with the block defined by division using roads, railways or tramway lines, other permanent facilities, rivers, waterways and the like, and the ward defined by Articles 252-20 and 252-20-2 of the Local Autonomy Act; that Article 3 requires an assembly resolution, the defining of areas and methods, the assigning of block symbols and house numbers, public notice, notification of interested parties and heads of relevant administrative organs, and a report to the prefectural governor; that Article 5 requires a town or aza area redrawn under its first paragraph to be given a name following the previous name so far as possible and otherwise easy to read and simple; that Article 5-2 requires prior publication of the draft, permits a request for amendment with the joint signatures of 50 or more qualified residents up to the day 30 days after publication, bars submission of the bill before that period runs, requires the substance of a request to be made public immediately and attached to the bill, requires a public hearing before the assembly votes, and leaves the assembly free to amend; that Article 6 paragraph 1 requires anyone to endeavour to use the assigned indication while paragraph 2 requires organs of the state and local government to use it in the basic resident register, the electoral roll, the corporate register and other public registers except where other law provides; that Article 7 bars collection of fees and other charges on applications to change residence entries in public registers or notarial documents; that Article 8 requires the municipality to erect a display board carrying the town or aza name with the block symbol or road name and requires the owner, manager or occupier to display the house number as municipal ordinance prescribes; that Article 9 requires a residential indication register and inspection by interested parties on request; that Article 9-2 requires endeavours to pass on changed names of historical standing through markers and the collection of materials; and that Article 12 gives the Minister for Internal Affairs and Communications the power to set technical standards.
https://laws.e-gov.go.jp/api/1/lawdata/337AC0000000119
Japan Post — postcode and barcode manual, guidance on postcodes
Confirmed that where a seven-digit postcode is written correctly the address may omit everything up to and including the city, ward, town or village name, that the writer should confirm the postcode is correct and that everything from the town area downwards must still be written; the worked examples for 100-0013 Kasumigaseki 1-chome 3-2 and 790-0066 Miyatamachi 8-5; that where the town-area name is prefixed with oaza or aza the omission may run through those characters, with the examples 333-0823 Oaza Ishigami 978 and 966-0049 Aza Nagaomote 3026-1; that where a town-area name prefixed with oaza is followed by aza the second aza may not be omitted, with the example at 038-3802 in Fujisaki Town shortening only as far as the oaza; that the customer service consultation centre answers postcode enquiries from 8:00 to 21:00 every day; and that postcode search and download services are provided on the company’s website.
https://www.post.japanpost.jp/zipcode/zipmanual/p39.html
Ministry of Internal Affairs and Communications — the residential indication system
Confirmed that the system is based on the Act on Residential Indication, Act No. 119 of 1962, that municipalities assign block symbols and house numbers after an assembly resolution and that procedures are fixed by municipal ordinance; that the ministry previously published newly implemented areas in the official gazette on the basis of municipal reports; that it reviewed the method, stopped using the gazette, and publishes the content of municipal reports on its own website for indications newly implemented on or after 1 January 2024; and that the batches posted are the 2025 fiscal year batch for 1 January to 31 December 2024, an additional posting for that batch, and the 2026 fiscal year batch for 1 January to 31 December 2025.
https://www.soumu.go.jp/main_sosiki/jichi_gyousei/daityo/juukyo_hyouji_seido.html
Japan Post — postcode search, 100-0013
Confirmed that the search returns Tokyo and Chiyoda Ward above a town area whose kana reading is the one romanised here as Kasumigaseki.
https://www.post.japanpost.jp/cgi-zip/zipcode.php?zip=1000013
Japan Post — postcode search, 790-0066
Confirmed that the search returns Ehime Prefecture and Matsuyama City above a town area whose kana reading is the one romanised here as Miyatamachi.
https://www.post.japanpost.jp/cgi-zip/zipcode.php?zip=7900066
Japan Post — postcode search, 333-0823
Confirmed that the search returns Saitama Prefecture and Kawaguchi City above a town area whose kana reading is the one romanised here as Ishigami.
https://www.post.japanpost.jp/cgi-zip/zipcode.php?zip=3330823
Japan Post — postcode search, 966-0049
Confirmed that the search returns Fukushima Prefecture and Kitakata City above a town area whose kana reading is the one romanised here as Nagaomote.
https://www.post.japanpost.jp/cgi-zip/zipcode.php?zip=9660049
Japan Post — postcode search, 038-3802
Confirmed that the search returns Aomori Prefecture and Fujisaki Town in Minamitsugaru County above a town area whose kana reading is the one romanised here as Fujisaki, and that it carries no reading for the aza name that follows.
https://www.post.japanpost.jp/cgi-zip/zipcode.php?zip=0383802
Last updated: October 2026
