# Your child's Japanese nationality: dual citizenship and the choice at 20

URL: https://japanhow.com/life/family/japanese-nationality-child-dual-citizenship/
Author: JapanHow editors
Updated: Oct 24, 2026

## Summary

As of October 2026, a child gets Japanese citizenship at birth if a parent is Japanese at the time of birth. Birth in Japan alone does not count. A child born abroad who also gets another nationality must have Japanese nationality reserved on the birth report within 3 months, or loses it. A dual national who became one by age 18 must choose a nationality by 20. A child acknowledged by a Japanese father after birth can become Japanese by notification before 18, with no fee.

## Key facts

- Japanese at birth if: A parent is Japanese at the birth
- Born abroad, dual: Reserve within 3 months
- Choice deadline: Age 20 (dual by 18)
- Acknowledged by a Japanese father: Notify before 18, no fee

Japanese citizenship for a child comes from a parent, not from the place of birth. Under the Nationality Act (国籍法), your child is Japanese at birth if **the father or mother is a Japanese national at the time of birth**. As of October 2026, a child born abroad who also gets another nationality must have Japanese nationality **reserved within 3 months** of the birth, and a child who became a dual national by age 18 must **choose one nationality by age 20**.

**The deadline most families miss:** 3 months, for births abroad (Without a reservation on the birth report, the child loses Japanese nationality back to the day of birth (Nationality Act, Article 12).)

This page explains what the law and the Ministry of Justice (法務省) say. It is not legal advice on your family's case. For that, ask the Legal Affairs Bureau (法務局), a Japanese embassy or consulate, or a lawyer or administrative scrivener (行政書士).

## Does Japan have birthright citizenship?

No. Article 2 of the Nationality Act makes a child Japanese at birth in three cases only:

| Case | Japanese at birth? |
|---|---|
| Father or mother is Japanese at the time of birth | Yes, wherever the child is born |
| Father died before the birth and was Japanese when he died | Yes |
| Born in Japan, and both parents are unknown or stateless | Yes |
| Born in Japan to two foreign parents with a known nationality | No |

If both of you are foreign nationals, your baby is not Japanese because it was born here. The baby needs your country's nationality and a status of residence (在留資格). See [what to do when your baby is born in Japan](/life/family/baby-born-japan-foreign-parents/).

## Is my child with a Japanese parent a dual national?

Often, yes. A child of one Japanese parent is Japanese at birth. Whether the child also has your nationality depends on your country's law, not Japan's.

The Ministry of Justice lists typical cases: the other parent's country passes nationality through the father or through either parent, or the child is born in a country that gives nationality to anyone born there (birthright, or jus soli). The Ministry says each country decides its own nationality and rules change, so ask that country's embassy whether your child holds its nationality.

**Acknowledgment before birth:** If the parents are not married and the father is Japanese, the timing of his acknowledgment (認知) matters. The Ministry's Q&A says a child acknowledged before birth (胎児認知) is Japanese at birth. A child acknowledged only after birth is not, and needs the notification described below.

## Japanese citizenship for a child born abroad: the 3-month reservation

A child born outside Japan who gets a foreign nationality at birth must have Japanese nationality reserved (国籍留保, kokuseki ryūho). Article 12 of the Nationality Act says that without it, the child **loses Japanese nationality retroactively from birth**.

The Family Register Act (戸籍法) sets the method:

- A person entitled to report the birth writes the reservation on the birth report (出生届).
- It is filed **together with the birth report, within 3 months of the birth** (Article 104). A birth abroad must be reported within 3 months anyway (Article 49).
- File at a Japanese embassy or consulate abroad, or at a municipal office in Japan.
- If a disaster or another cause outside your control stops you, you have 14 days from when filing becomes possible.

A child born in Japan to a Japanese parent does not need a reservation. Article 12 covers births abroad only. The birth report in Japan is due within 14 days.

### What if we missed the 3 months?

The child can reacquire Japanese nationality by notifying the Minister of Justice if, at the time of filing, the child is **under 18** and has a **domicile (住所) in Japan** (Article 17). The Ministry's Q&A says domicile means the main base of the child's life: a tourist trip or a short family visit does not count. The filing is at the Legal Affairs Bureau.

## The choice of nationality: what happens at 20?

Article 14 of the Nationality Act requires a dual national to choose one nationality (国籍選択, kokuseki sentaku). The deadline depends on when the person became a dual national:

| Became a dual national | Choose by |
|---|---|
| Up to age 18 (including at birth) | Age 20 |
| After turning 18 | Within 2 years |

These limits apply from 1 April 2022, when Japan lowered the age of adulthood to 18. Before that, the limits were 22 and 2 years. Under the 2018 amending law, people who were already dual nationals and **20 or older on 1 April 2022 still follow the old rule**: choose by 22, or within 2 years if they became dual nationals at 20 or older. Those aged 18 or 19 on that date were treated as becoming dual nationals that day.

The choice must be the person's own decision. For a child under 15, the legal representative (usually a parent) files (Article 18).

### How do you choose?

The Ministry of Justice describes four routes:

| To keep | Route | Where |
|---|---|---|
| Japanese nationality | Give up the other nationality under that country's law, then file a foreign nationality loss report (外国国籍喪失届) with proof | Municipal office, or embassy or consulate |
| Japanese nationality | File a nationality choice notification (国籍選択届): a declaration choosing Japan and renouncing the other nationality | Municipal office, or embassy or consulate |
| The other nationality | File a renunciation of Japanese nationality (国籍離脱届) | Legal Affairs Bureau for your address, or embassy or consulate |
| The other nationality | Choose it under that country's law, then file a nationality loss report (国籍喪失届) with proof | Municipal office, or embassy or consulate |

The Ministry's page for the nationality choice notification says there is **no fee**. It lists no attachments, except one copy of the family register (戸籍謄本) when filing at an embassy or consulate and the register is not computerized.

**The declaration may not end the other nationality:** Filing the 国籍選択届 meets the duty to choose under Japanese law. But the Ministry says some countries don't remove their nationality because of it. In that case, Article 16 says the person must make efforts (努めなければならない) to give up the other nationality. How to do that depends on that country: ask its embassy.

## What happens if a dual national doesn't choose?

Here is what the law and the Ministry say, and nothing more:

- Missing the deadline does not cancel the duty. The Ministry says you still have to choose.
- The Minister of Justice **may** send a written notice (催告) telling the person to choose (Article 15). If the address is unknown, the notice can be published in the Official Gazette (官報).
- If the person does not choose Japanese nationality within **1 month** of receiving the notice, they lose Japanese nationality when that month ends, unless a disaster or another cause outside their control prevented the choice.
- A city office that finds, while handling family register work, that someone has not chosen in time must notify the Legal Affairs Bureau (Family Register Act, Article 104-3).

The law says "may", and the Ministry pages we checked don't say how often the notice is used. Don't rely on what you hear from other families: the legal duty is the same either way.

Two other rules can end Japanese nationality. A Japanese national who **voluntarily takes another nationality**, for example by naturalizing in another country, loses Japanese nationality (Article 11). And someone who declared for Japan but kept the other nationality can lose Japanese nationality if they take a public post in that country reserved for its nationals, when the Minister finds this clearly contrary to their choice (Article 16).

## Acknowledged by a Japanese father: acquisition by notification

A child acknowledged by a Japanese father after birth can become Japanese by notification (届出による国籍取得) under Article 3. The conditions:

- The child is **under 18** when filing (under 20 before 1 April 2022).
- The father was Japanese **at the child's birth**.
- The father is Japanese now, or was Japanese when he died.
- The child has never been Japanese.

The child becomes Japanese on the day of the notification, not from birth. A false notification is a crime: up to 1 year of imprisonment or a fine of up to ¥200,000 (Article 20).

If a court's acknowledgment ruling is final, the Ministry says the parents' account, travel records and other relationship proof are not needed.

## What does this mean for foreign parents?

If you are the foreign parent, your child's Japanese nationality runs through your Japanese spouse or partner. Three things are on you to check:

1. **Your own country's rules.** Whether your child holds your nationality, and whether your country lets them keep it after a Japanese declaration, is decided by your country. Ask your embassy.
2. **The 3-month window for births abroad.** If you give birth outside Japan, put the reservation on the birth report in time.
3. **Your own path.** The child's nationality does not change yours. If you want Japanese nationality yourself, that is [naturalization (帰化)](/visa/naturalization/naturalization-japan-process/), which requires giving up your current nationality in principle. Compare it with permanent residency in [PR vs naturalization](/visa/residency/permanent-residency-vs-naturalization/).

For your own status, see [the spouse visa](/visa/visas/spouse-visa-japan/) if you are married to a Japanese national, or [long-term resident status](/visa/visas/long-term-resident-visa-japan/) if you raise a Japanese child after a divorce.

**More guides:** [baby born in Japan to foreign parents](/life/family/baby-born-japan-foreign-parents/) · [giving birth in Japan](/life/family/giving-birth-japan-foreigners/) · [international marriage in Japan](/life/family/international-marriage-japan/) · [naturalization process](/visa/naturalization/naturalization-japan-process/) · [PR vs naturalization](/visa/residency/permanent-residency-vs-naturalization/)

## Questions people ask

### Does Japan have birthright citizenship?

No. Under Article 2 of the Nationality Act, birth in Japan makes a child Japanese only if both parents are unknown or stateless. Otherwise Japanese nationality comes from a parent who is Japanese at the time of birth.

### Does Japan allow dual citizenship for children?

A child can hold Japanese and another nationality until the legal deadline. If the child became a dual national by age 18, the Nationality Act says they must choose one nationality by age 20.

### What is kokuseki sentaku?

国籍選択 (kokuseki sentaku) is the choice of nationality that Article 14 of the Nationality Act requires from dual nationals. To keep Japanese nationality you either give up the other one under that country's law or file a nationality choice notification (国籍選択届), which has no fee.

### How does a child born abroad get Japanese citizenship?

If a parent is Japanese, the child is Japanese at birth. If the child also gets another nationality at birth, the parents must report the birth with a reservation of Japanese nationality within 3 months, at a Japanese embassy or consulate or a municipal office.

### My child was acknowledged by a Japanese father after birth. Is the child Japanese?

Not automatically. The child can acquire Japanese nationality by notifying the Minister of Justice before turning 18, if the father was Japanese at the birth and still is (or was when he died). The filing is at the Legal Affairs Bureau, or at a Japanese embassy or consulate if you live abroad, and has no fee.

## Sources

- [国籍法 (Nationality Act)](https://laws.e-gov.go.jp/law/325AC0000000147), e-Gov (Digital Agency) (accessed Oct 24, 2026)
- [戸籍法 (Family Register Act)](https://laws.e-gov.go.jp/law/322AC0000000224), e-Gov (Digital Agency) (accessed Oct 24, 2026)
- [国籍Q&A](https://www.moj.go.jp/MINJI/minji78.html), Ministry of Justice (法務省) (accessed Oct 24, 2026)
- [国籍選択について](https://www.moj.go.jp/MINJI/minji06.html), Ministry of Justice (法務省) (accessed Oct 24, 2026)
- [国籍選択の届出](https://www.moj.go.jp/ONLINE/NATIONALITY/6-4.html), Ministry of Justice (法務省) (accessed Oct 24, 2026)
- [国籍取得の届出 (認知された子)](https://www.moj.go.jp/ONLINE/NATIONALITY/6-1.html), Ministry of Justice (法務省) (accessed Oct 24, 2026)