How to get your ancestor's koseki from outside Japan
The koseki is the key record for Japanese family history. Many families of emigrants to Hawaii, the mainland US, Canada, Brazil and Peru can still obtain the registers their ancestors appear in. The oldest registers you can request usually date from 1886. This guide explains the process for people who live outside Japan and don't read Japanese.
1. Who can request a koseki
Under Japan's Family Register Act, the people listed in a register, their spouses, and their direct ancestors and direct descendants may request copies. You do not need to be a Japanese citizen. A great-grandchild in California or São Paulo is a direct descendant of a great-grandfather born in Hiroshima.
Siblings, cousins, aunts and uncles are not direct lines. If your ancestor is a great-uncle, you generally cannot request his register yourself unless it is also the register of your direct ancestor (which is common, because whole households were registered together).
Someone else can request on your behalf with your power of attorney. If you pay a person in Japan to prepare and file the request, that person should be a licensed professional such as an administrative scrivener (gyōseishoshi). Preparing official documents for others for a fee is restricted by law in Japan.
2. Find the honseki and the kanji surname
A koseki is filed by its honseki (本籍, registered domicile), not by where people lived. To request it you need, at minimum:
- The prefecture, district/city and village of the honseki — ideally down to the lot number (番地, banchi)
- The name of the head of the household or of your ancestor, in kanji
Romanized names are ambiguous: "Ito" can be 伊藤, 伊東 or 井藤. Places to look for the kanji and the honseki:
| Source | What it often shows |
|---|---|
| Japanese passports and emigration papers kept by the family | Often among the most useful papers to check for the home village and the name in kanji |
| Hawaii and US immigration records, ship manifests | Prefecture and village in romanized form |
| WWII incarceration records of Japanese Americans (War Relocation Authority, or WRA, files) | Prefecture of origin; sometimes village |
| Alien registration, naturalization files | Birthplace, sometimes in kanji |
| Gravestones, butsudan (family altar) tablets, letters from Japan | Kanji names, family crest, return addresses in the home village |
| Japanese consulate-related family papers (common in Brazil and Peru) | May show the home prefecture or village and kanji names |
If you only know the prefecture, start with older relatives and family papers. Envelopes from relatives in Japan are a goldmine: the return address is frequently the home village.
3. Find today's city office
Most villages of the Meiji era (1868–1912) no longer exist under their old names. Japan merged municipalities in large waves (1888–1889, the 1950s, and 1999–2010). The koseki of a "village" is now kept by whichever city or town absorbed it.
Example: Niho-jima Village, Aki District, Hiroshima is today part of Minami-ku, Hiroshima City. The request goes to the ward office of Minami-ku.
Search the old village name in Japanese Wikipedia (most villages have a page with a merger history), or order a Roots Report, and we will identify the office for you.
4. Gather proof of descent
The office must be able to see that you are a direct descendant of someone in the register. You will usually need documents that connect each generation, for example:
- Your own birth certificate (showing your parents)
- Your parent's birth certificate (showing your grandparents), and so on, up to the person in the koseki
- Marriage certificates where a surname changed
- A copy of your photo ID (passport or driver's license)
Many offices ask for Japanese translations of foreign certificates. Requirements vary a lot between offices, so read the instructions or ask before sending. Mismatched names (an English name, a Japanese name and a married name for the same person) are a common reason requests stall. Include anything that ties the names together.
5. Prepare the request
Most cities publish a mail-in request form (郵送請求書) on their website. Typical items:
- Your name, address, phone number and email, and your relationship to the person in the register
- The honseki and the name of the index person (筆頭者, hittōsha), the first person listed in the register
- Which certificate you want (see the table below) and how many copies
- Purpose of the request (for example, "family history research")
- Your signature
| Japanese | English | What it is | Standard fee |
|---|---|---|---|
| 戸籍謄本 / 戸籍全部事項証明書 | Current register | A register still in use | ¥450 (about US$3) |
| 除籍謄本 / 除籍全部事項証明書 | Closed register | A register everyone has left (death, marriage, move) | ¥750 (about US$5) |
| 改製原戸籍謄本 | Pre-reformat register | Older version replaced when the format changed | ¥750 (about US$5) |
For emigrant families, the register you want is almost always a closed register (除籍) or a pre-reformat register (改製原戸籍). Ask for "all registers in which [ancestor] appears" if you are unsure; the office will tell you the total fee. Dollar amounts are rough and depend on the exchange rate.
Note: Japan's nationwide issuance system (広域交付), launched in 2024, lets people request registers at any city office, but only in person with Japanese ID. It does not help requests from abroad.
6. Pay the fee from abroad
This is where many overseas requests get stuck. Japanese city offices traditionally accept fees by mail only as teigaku kogawase (定額小為替, postal money orders), which can only be bought at a post office in Japan. Options that offices accept vary:
| Method | Where it works | Notes |
|---|---|---|
| Online credit card payment | Some cities (for example, Kobe, Sendai and Ikeda accept online payment for overseas requests) | Easiest if available. Check the city's "requests from abroad" page. |
| A helper in Japan sends postal money orders | Widely accepted (Sendai, for example, explicitly allows this) | A relative or friend in Japan mails the money orders separately; you note this on your request. |
| International Reply Coupons | Ending in 2026 | According to Ikeda City, Japan Post stopped selling them on September 30, 2026, and they cannot be exchanged after December 31, 2026, in Japan or abroad. Do not rely on them for new requests. |
| International postal money order | Limited | From the US, service ended in March 2020. Check your own postal service; Canada Post and Brazil's Correios have their own rules. |
| Cash by registered mail | Some offices, if your post office can send yen by registered mail | Rarely practical. |
Sources: Kobe City, Sendai City, Ikeda City (Japanese).
7. Mail it, and what you will receive
Send the form, proof of descent, ID copy, payment and a return envelope (or the return-postage method the office accepts) by international mail. Expect two to six weeks, sometimes longer if the office writes back with questions.
You will receive certified copies. Older registers are photocopies of handwritten originals: dense vertical columns, brush or pen script, old character forms and imperial-era dates. Each register usually points to the previous one (where someone came from), so one request often leads to the next, older register.
8. Reading what arrives
Unfamiliar terms are explained in our glossary. Even fluent Japanese readers struggle with Meiji-era handwriting. Machine translation will not read it reliably. When your registers arrive, you can:
- Ask volunteer communities (FamilySearch Community, r/Genealogy) for help with a few lines
- Order a Koseki Family Tree: full transcription, English translation, Western dates, modern place names and a family tree, with any uncertain readings flagged
Want this done for your family?
A Roots Report ($390) tells you about your ancestral village and what the old records say about the families of your name there, and includes a koseki request guide written for your family. When the registers arrive, the Koseki Family Tree ($1,000 for up to 6 registers) turns them into English and a family tree. Not sure yet? Start with a Roots Snapshot ($29).