How to Get a Japanese Koseki (Family Register) from Overseas: A Step-by-Step Guide for 2026

Many visa and family procedures in Japan require a koseki tohon (戸籍謄本), a certified copy of a Japanese family register. The problem is that koseki certificates are issued only by Japanese municipal offices, and Japanese embassies and consulates do not issue them.

So what can you do if you live outside Japan? This guide explains who can request a koseki, how to apply by mail from abroad, how to pay the fees, and what to do when the process gets complicated.

What is a koseki?

A koseki is Japan’s official family register. It records a Japanese national’s birth, marriage, divorce, parent–child relationships, adoption, and death. A certified copy of the whole register is called a koseki tohon (officially 戸籍全部事項証明書, “certificate of all matters in the family register”).

Other certificates you may come across:

Foreign nationals do not have their own koseki. However, when a foreign national marries a Japanese national, the marriage is recorded in the Japanese spouse’s koseki.

When do you need a koseki? Key visa cases

For immigration purposes, a koseki is the official Japanese proof that you are related to a Japanese national. The Immigration Services Agency of Japan lists it as a required document for the visas below.

1. Spouse of a Japanese national (“Spouse or Child of Japanese National” visa)

If you are married to a Japanese national and want to live in Japan, you usually apply for the Spouse or Child of Japanese National visa (日本人の配偶者等). The main documents proving your marriage are:

• Your Japanese spouse’s koseki tohon, showing the marriage entry
• A marriage certificate issued by your own country

If the marriage has been registered but does not yet appear in the koseki (this can take some time, especially when the marriage was reported through an embassy or consulate), you may submit the koseki together with a certificate of acceptance of the marriage notification (婚姻届受理証明書).

Tip: Before you apply, make sure that the marriage has been registered in Japan and appears in your spouse’s koseki. If your Japanese spouse lives abroad with you, they can request their own koseki by mail as explained below.

2. Nikkei second generation (Nisei)

A second-generation Japanese descendant is the child of a Japanese national. Depending on the circumstances, the visa is usually one of these:

• Spouse or Child of Japanese National: generally used when the parent was a Japanese national when the applicant was born.
• Long-Term Resident (定住者) under Long-Term Resident Notification No. 3 (定住者告示3号): may apply in some cases, for example when the parent had already lost Japanese nationality when the applicant was born. Notification No. 3 covers the biological child of a person who was born as a child of a Japanese national. This is the same notification that covers many Nikkei 3rd Generation applicants. (See our Long-Term Resident (Nikkei 3rd Generation) page.)

Typical lineage documents include:

• The Japanese parent’s koseki tohon or joseki tohon
• The applicant’s birth certificate (issued by the country of birth)
• The parents’ marriage certificate, where applicable

3. Nikkei third generation (Sansei)

A third-generation Japanese descendant is the grandchild of a Japanese national. Sansei generally apply for the Long-Term Resident visa (定住者). The Spouse or Child of Japanese National visa is not available to them.

To prove the link from the Japanese grandparent to the applicant, the Immigration Services Agency asks for:

• The Japanese grandparent’s koseki tohon or joseki tohon
• Marriage certificates of the grandparents and of the parents
• Death certificates of grandparents or parents, if applicable
• The applicant’s birth certificate

In Nikkei cases, the grandparent’s register has often been closed or rewritten over the years. You may need joseki or kaisei-gen koseki rather than a current koseki tohon, and sometimes several registers to follow the family line. Finding the grandparent’s honseki is often the biggest challenge.

For the full document list, see our Long-Term Resident (Nikkei 3rd Generation) page.

Other situations

• Inheritance in Japan: to identify all legal heirs.
• Marriage, divorce, or other family registrations in Japan or abroad.

Important: For immigration applications, documents issued in Japan, including koseki certificates, must be issued within the last three months. Documents in a foreign language (such as foreign birth or marriage certificates) must come with a Japanese translation. Plan your koseki request so it arrives shortly before you apply.

Step 1: Find the honseki (registered domicile)

A koseki is kept at the municipal office (city, ward, town, or village) of the honseki (本籍), the registered domicile. The honseki is not necessarily where the person lives or was born.

You will need:

• The full address of the honseki
• The name of the head of the register (筆頭者, hittosha)

If you don’t know the honseki, check old family documents such as an old koseki copy, a Japanese passport, marriage or birth records, or ask relatives in Japan. Place names may have changed because of municipal mergers, but the municipality that absorbed the old town keeps the records.

Step 2: Confirm that you can request it

Under Japan’s Family Register Act (戸籍法), the following people can request a koseki without having to state a special reason:

• The person recorded in the koseki
• Their spouse (including a foreign spouse)
• Their direct ancestors (parents, grandparents, etc.)
• Their direct descendants (children, grandchildren, etc.)

Other people, such as siblings, cousins, or friends, generally need either a power of attorney from an eligible person or a specific legitimate reason.

Step 3: Choose how to request it

Option A: Request by mail directly from the municipality

Most municipalities accept mail requests from overseas. Requirements vary by municipality, so always check the website of the office that holds the koseki. Typically you will need:

1. Application form for mail requests (郵送請求書), completed in Japanese. Many municipalities provide a downloadable form.
2. Copy of your ID. Many offices require a document showing both your name and your current overseas address. If your passport does not show your address, add a copy of a utility bill, bank statement, lease, or residence certificate issued by the embassy or consulate. Some offices also ask for a Japanese translation.
3. Payment of the fee (see below).
4. Return envelope with your full overseas address, or a request to send it by EMS.
5. Information about the koseki: honseki, name of the head of the register, type and number of certificates, and purpose (for example, “visa application”).
6. Proof of relationship if the family link does not appear in the requested koseki (for example, your own birth certificate or your parent’s koseki).

Typical fees (standard national amounts; check your municipality):

• Koseki tohon/shohon: ¥450 per copy
• Joseki or kaisei-gen koseki: ¥750 per copy

How to pay from abroad. This is often the hardest part, because Japanese teigaku kogawase (定額小為替, postal money orders) can only be bought in Japan. Depending on the municipality, you may be able to use:

• Online payment by credit card (or other cashless payment) through the municipality’s online system. This option is increasingly common in larger cities.
• International Reply Coupons (IRCs), bought at your local post office. Some municipalities accept them as payment or for return postage.
• Japanese yen cash by international registered mail
• Postal money orders bought in Japan by a relative or friend and sent to you or directly to the office

Many municipalities do not accept bank transfers or foreign currency. Confirm accepted payment methods before you send anything.

Timing. Allow about 1–2 weeks for processing, plus international mail time both ways. Several municipalities recommend using EMS in both directions for speed and tracking.

Option B: Ask a relative or friend in Japan

A relative in Japan who is a spouse, direct ancestor, or direct descendant of the person in the koseki can request it in their own right. Other people can request it with your power of attorney (委任状). The letter should clearly state:

• Your name, address, date of birth, and signature
• The agent’s name and address
• The honseki and head of the register
• The type and number of certificates

Option C: Visit Japan in person (nationwide issuance)

Since March 1, 2024, the Koseki Nationwide Issuance system (戸籍証明書の広域交付) lets eligible people get koseki and joseki certificates at any municipal office in Japan, not only at the honseki office. However:

• Only the person, their spouse, direct ancestors, and direct descendants can use it
• You must visit in person with photo ID (such as a passport or My Number Card)
• Mail and agent requests are not accepted under this system
• Some older or non-computerized registers, as well as partial certificates, are not covered

This is convenient if you are visiting Japan, but it doesn’t help if you can’t travel.

Option D: Ask a professional (gyoseishoshi)

A licensed administrative scrivener (gyoseishoshi, 行政書士) handling your visa application can request koseki certificates needed for that work, within the limits of the law. A professional can also help trace an unknown honseki, collect older registers, and check whether your documents are enough for your application.

Common problems and tips

• “I don’t know the honseki.” Start with any Japanese documents your family has. For Nikkei descendants, older family records, emigration documents, or relatives in Japan often provide the key clue.
• “The old address no longer exists.” Town names often changed after municipal mergers. The successor municipality holds the records.
• “The koseki is handwritten and hard to read.” Older registers (joseki and kaisei-gen koseki) are often handwritten in old-style Japanese. A professional translation may be needed for use outside Japan. For immigration applications in Japan, Japanese-language koseki are submitted as they are.
• “My old koseki copy is from years ago.” It is useful for research, but you will usually need a newly issued certificate for your application.
• “Mail service to my country is suspended.” Japan Post occasionally suspends service to some countries. Check Japan Post’s website, or use a relative or professional in Japan instead.

Quick checklist

Need help? Contact TKG Immigration Consulting Office

Getting a koseki from abroad can take time, especially when the honseki is unknown or several generations of records are needed. We support clients in Japan and overseas with:

• Collecting koseki, joseki, and kaisei-gen koseki
• Tracing family records for Nikkei (Japanese descendant) applicants
• Spouse visa and Long-Term Resident visa applications
• Checking whether your documents meet immigration requirements

Contact us for a consultation.

This article provides general information and is not legal advice. Procedures, fees, and payment methods vary by municipality and may change, so please check with the relevant municipal office before applying.