How to Get Foreign Citizenship [2026]: 5 Routes, Requirements and Costs by Country for Japanese Nationals

October 20, 2026

Taiga Sato

There are five ways for a Japanese national to obtain a foreign citizenship (i.e., a foreign nationality): (1) live in the country and naturalize, (2) marry a national of that country and use a shorter naturalization requirement, (3) inherit the nationality of a parent or grandparent (descent), (4) obtain citizenship through investment or a donation (citizenship by investment), and (5) special naturalization based on merit or achievements. The most common is (1): for example, the United States requires 5 years after obtaining a green card, Canada requires 1,095 days of physical presence in 5 years, and Germany requires 5 years of residence. The fastest route for those willing to pay is (4): Nauru, Vanuatu and several Caribbean countries grant citizenship for a donation of US$90,000 to US$250,000.

*Amounts and rules are as of October 18, 2026. This article is an English version of our Japanese guide, adapted for foreign residents of Japan and international investors.

However, a Japanese national who voluntarily acquires a foreign nationality automatically loses Japanese nationality at that moment (Article 11(1) of the Nationality Act). After acquisition, there are also procedures on the Japanese side, such as filing a report of loss of nationality, returning the Japanese passport and, if you live in Japan, obtaining a status of residence. Based on information published by each country's immigration authority, Japan's Ministry of Justice, Ministry of Foreign Affairs and others, this article covers:

The five routes to a foreign nationality, and the naturalization requirements and costs of major countries
Countries that grant citizenship by investment, and the program changes in 2025–2026
What to check before applying (whether permanent residence is enough, family, taxes)
The Japanese documents required for applications, and the procedures on the Japanese side after acquisition

Contents

Conclusion: there are five ways to obtain a foreign nationality, and Japanese nationality is lost on acquisition
Five routes to a foreign nationality
Naturalization requirements and costs in major countries [2026]
Countries offering citizenship by investment
How many Japanese nationals acquire a foreign nationality?
What to check before acquiring
Japanese documents required for the application
Procedures on the Japanese side after acquisition
FAQ
Summary: compare the routes, and what you lose, first

Conclusion: there are five ways to obtain a foreign nationality, and Japanese nationality is lost on acquisition

The ways a Japanese national can obtain a foreign nationality, and the effect on Japanese nationality, are summarized below.

For Japanese nationals: ways to obtain a foreign nationality and the effect on Japanese nationality (as of October 2026)
Route	Typical requirements	Japanese nationality
(1) Naturalization through residence	In many countries, 5–10 years of permanent residence or residence. Many countries require language and civics tests	Lost on acquisition
(2) Marriage (naturalization as a spouse)	Few countries grant nationality through marriage alone; the usual effect is a shorter residence requirement for naturalization (UK, US, South Korea, etc.)	Lost if acquired by application
(3) Descent / ancestry	Inheriting the nationality of a parent or grandparent (e.g., Ireland's grandparent route)	Lost if acquired by application or registration. A person who has held a foreign nationality since birth is subject to the choice-of-nationality rules (if born abroad, this assumes Japanese nationality was reserved within 3 months of birth)
(4) Investment / donation (citizenship by investment)	From US$200,000 minimum in the five Caribbean countries, US$130,000 in Vanuatu, US$90,000 in Nauru, etc.	Lost on acquisition
(5) Special naturalization based on merit	Discretionary naturalization by the state for athletes, researchers and others	Lost on acquisition

Article 11(1) of Japan's Nationality Act provides that a Japanese national who acquires a foreign nationality by his or her own choice loses Japanese nationality. Any acquisition by your own application, such as naturalization or citizenship by investment, counts as "by one's own choice", and the same applies to acquisition by declaration or registration, and to cases where a parent applies on behalf of a minor child. Even if the other country allows dual nationality, Japanese nationality is not retained. On the other hand, where a foreign law automatically confers its nationality upon marriage, for example, the person did not apply, so Japanese nationality is not lost and the person becomes a dual national. Even in that case, however, a nationality must be chosen within 2 years of becoming a dual national (or by age 20 if this happens before age 18) (Ministry of Justice, Nationality Q&A).

How Article 11 of the Nationality Act applies in detail, whether each country allows dual nationality, and the choice of nationality are explained in Countries that allow dual citizenship. This article focuses on how to obtain a foreign nationality and the preparations and procedures on the Japanese side before and after acquisition.

Five routes to a foreign nationality

(1) Naturalization through residence

This is the most common route. You live in the country on a work visa or permanent residence and apply for naturalization after meeting the required number of years. In many countries, the requirements are holding permanent residence (or a similar long-term status), having been physically present for a minimum number of days, passing language and civics tests, and having no criminal record. Many countries require permanent residence first, so in practice the path "work visa → permanent residence → naturalization" often takes around 10 years. Countries where permanent residence is easier to obtain are compared in The easiest countries to get permanent residence.

(2) Marriage (naturalization as a spouse)

Only a few countries automatically grant nationality on marriage alone. Most countries shorten the residence period required for naturalization for spouses of their nationals. For example, in the UK a spouse can apply immediately with 3 years of residence and settlement (indefinite leave); in the US, 3 years after obtaining a green card; and in South Korea, after 2 years of residence during the marriage. On the other hand, Canada and New Zealand have no shortened route for spouses.

(3) Descent / ancestry

Some countries allow a person whose parent or grandparent is a national to inherit the nationality by application or registration. Ireland grants nationality through Foreign Births Registration if a grandparent was born on the island of Ireland (€278 for an adult). Italy, by a 2025 law, limited acquisition by descent for people born abroad who hold another nationality to cases such as where a parent or grandparent holds (or held) only Italian nationality, or where a parent lived in Italy for 2 years or more before the child's birth.

(4) Investment / donation (citizenship by investment)

These programs grant citizenship without any residence record in exchange for a donation to a government fund or an investment in designated real estate. The fastest take 3–4 months, but for Japanese nationals Japanese nationality is lost just as in (1), and there is a continuing trend of restricting the countries that holders of these passports can visit (see the next section).

(5) Special naturalization based on merit

This is a discretionary grant of nationality to people who have contributed to the country in sports, academia, culture and so on. In many countries it is an exceptional measure, not something you can apply for on your own initiative.

Naturalization requirements and costs in major countries [2026]

The requirements for naturalization through residence in major countries are as follows (based on information published by each country's immigration and citizenship authorities; fees are per adult).

Naturalization requirements in major countries (as of October 2026)
Country	Residence requirement	Shorter route for spouses	Language / tests	Application fee
United States	5 years after obtaining a green card	3 years for spouses of US citizens	English and civics tests	US$710 online, US$760 on paper. A proposed fee increase was published in June 2026 (not yet in effect)
Canada	1,095 days of physical presence as a permanent resident in 5 years	None	Ages 18–54: English or French, and the citizenship test	CA$653
Australia	4 years of residence (including the last year as a permanent resident)	—	Citizenship test	A$595
New Zealand	5 years on a residence visa, with at least 1,350 days in total and at least 240 days in each year	None	Basic English	NZ$641
United Kingdom	Usually 12 months after obtaining indefinite leave to remain (ILR)	Spouses of British citizens can apply with 3 years of residence and ILR	English and the "Life in the UK" test	£1,709 + £130 ceremony
Ireland	5 years of residence in the last 9 years (with the final year continuous)	3+ years of marriage and 3 years of residence in the last 5	None at present	€175 application + €950 certificate
Germany	5 years of residence (the 3-year fast track was abolished in 2025)	Spouses of Germans: 3 years of residence + 2 years of marriage	German at B1 and the naturalization test	€255
France	5 years of residence	Acquisition by declaration after 4+ years of marriage	French at B2 and a civics test	€255
Netherlands	5 years of residence	Spouses/partners of Dutch nationals: 3 years of living together	Civic integration exam	€1,139
Sweden	8 years of residence (from June 6, 2026; previously 5 years)	7 years (with conditions such as 5 years of living together)	Proof of language and civics knowledge, income requirement	SEK 2,900
Switzerland	10 years of residence and a permanent residence permit (C permit)	5 years of residence in total + 3 years of marriage	German or another national language	CHF 100 federal fee + cantonal and municipal fees
Portugal	10 years for nationals of countries outside the EU and the Portuguese-speaking world (amendment effective May 19, 2026; previously 5 years)	More than 3 years of marriage	Portuguese, knowledge of culture and history	€250
Spain	10 years as a rule	1 year of marriage to a Spanish national	Language and sociocultural tests	€104.05
Italy	10 years for non-EU nationals	2 years after marriage if living in Italy, 3 years of marriage if living abroad (halved if there are children)	Italian at B1	€250
Singapore	At least 2 years as a permanent resident, aged 21 or over	2 years as a permanent resident and 2 years of marriage (no shortening of the period)	—	S$180 in total
South Korea	5 years with permanent resident status	2 years of residence during the marriage, etc.	Korean language and understanding of Korean customs	—
Taiwan	Residence of more than 183 days a year for 5 consecutive years	3 years	Basic Chinese, etc.	—
Brazil	4 years of residence	1 year	Portuguese	—
Panama	5 years of residence	3 years for spouses of Panamanians	Spanish, knowledge of geography and history	—

A "—" in the table means we could not confirm an official statement on a shorter spousal route or the fee. In 2025–2026, a growing number of countries have tightened their naturalization requirements. Portugal extended the residence requirement for nationals of countries outside the EU and the Portuguese-speaking world from 5 to 10 years, Sweden from 5 to 8 years, and Germany abolished its 3-year fast track. The UK's "10-year settlement", Ireland's "8 years" are still under consideration and were not in force as of October 2026 (the Netherlands' "10 years" proposal was reportedly dropped in the January 2026 coalition agreement). If you are choosing a destination with naturalization in mind, check the latest official information so that you can judge by the requirements that will apply at the time you apply.

Countries offering citizenship by investment

The main countries where citizenship can be obtained through a donation or investment, without any residence record, are listed below (minimum amount for a single applicant). For Japanese nationals, citizenship by investment cannot be used to hold a second passport alongside a Japanese one: on acquisition, the Japanese passport becomes invalid.

Main citizenship-by-investment countries (as of October 2026, minimum for a single applicant)
Country	Minimum amount	Notes
Nauru	US$90,000	Price valid until December 31, 2026. Processing 3–4 months
Vanuatu	US$130,000	Due diligence and other fees are separate. The regulations were amended in March 2026 and the amended amounts have yet to be published. Biometric enrolment is required for passport issuance
Dominica	US$200,000	Donation to the Economic Diversification Fund, or real estate. Official processing guideline 3–4 months (in practice it often takes longer)
Antigua and Barbuda	US$230,000	National Development Fund. Plus a US$10,000 processing fee, etc.
Grenada	US$235,000	National Transformation Fund
Saint Lucia	US$240,000	National Economic Fund (same amount for up to 4 people)
Saint Kitts and Nevis	US$250,000	Same amount for a family of up to 4
Turkey	Real estate of US$400,000 held for 3 years	The fund route is US$500,000

The five Caribbean countries (Dominica, Antigua and Barbuda, Grenada, Saint Lucia, and Saint Kitts and Nevis) set a floor of US$200,000 under a 2024 regional agreement. Restrictions on the usefulness of the passports obtained are spreading:

EU: From December 2025, operating a citizenship-by-investment program became a ground for suspending visa-free access. Vanuatu's visa exemption was ended by a December 2024 decision and abolished in February 2025
United Kingdom: Nationals of Dominica and Vanuatu (from July 2023), Nauru (from December 2025) and Saint Lucia (from March 2026) need a visa
United States: From January 1, 2026, entry by nationals of Antigua and Barbuda and Dominica is partially restricted
Japan: Nauru, Vanuatu and the five Caribbean countries are not on Japan's visa exemption list (Turkey is), so their nationals need a visa to enter Japan even for a short stay. Those who naturalize in the US, Canada, the UK, etc. do not need a visa for a short stay

Citizenship by investment is not "a substitute for a Japanese passport". Costs by country are compared in Residency and citizenship costs by country.

How many Japanese nationals acquire a foreign nationality?

Comprehensive official statistics on the number of Japanese nationals who acquire a foreign nationality are limited. The following figures are useful as a reference:

Japanese permanent residents living abroad: 588,486 (as of October 1, 2025, Ministry of Foreign Affairs "Annual Report of Statistics on Japanese Nationals Overseas"), the highest since 1991. The Ministry's "permanent residents" are people living abroad indefinitely while keeping Japanese nationality (many hold local permanent residence), and some of them go on to naturalize
Countries with the most permanent residents: the United States, Australia, Canada, Brazil and the United Kingdom, in that order
Declarations of renunciation of nationality: 588 people renounced Japanese nationality themselves in 2025 (Ministry of Justice), mainly people who held both Japanese and a foreign nationality from birth. People who lost Japanese nationality by naturalizing abroad are counted separately and handled by a report of loss of nationality

Well-known examples include the Nobel Prize in Physics laureates Yoichiro Nambu (2008), Shuji Nakamura (2014) and Syukuro Manabe (2021), all of whom were US citizens when they received the prize. The typical pattern is that a person who moved their research or work base abroad naturalizes after living there for many years.

What to check before acquiring

Is permanent residence enough?

If you simply want to live, work and own a home abroad, permanent residence is enough in many countries, and a Japanese national keeps Japanese nationality with permanent residence. What naturalization adds is mainly the right to vote in that country, that country's passport, and a status that is not lost even if you live outside the country for a long time. Permanent residence can be lost after a long absence (e.g., Australia's resident return visa, Singapore's re-entry permit), so the decision depends on where you plan to live in the future.

Family and children's nationality

For Japanese nationals: if a parent applies for a foreign nationality on behalf of a minor child, the child also loses Japanese nationality. On the other hand, a child who has held a foreign nationality since birth (such as a child born in the US) does not lose Japanese nationality because a parent naturalizes. If a foreign law automatically grants nationality to a child when the parent naturalizes, check how this is treated with the Legal Affairs Bureau or a Japanese embassy/consulate in advance. If your child may live in Japan in the future, you can consider the child's nationality separately. A child born to a Japanese parent and a foreign parent may be a dual national from birth, in which case the procedures for reserving and choosing nationality are required (Countries that allow dual citizenship).

Tax depends on residence, not nationality

Japanese income tax liability is determined by whether you have a domicile in Japan, not by nationality. Even with a foreign nationality, you are a Japanese tax resident if your base of life is in Japan. The exit tax on departure (taxation on transfer of residence abroad) applies regardless of nationality. For inheritance tax, the scope of taxation is determined by the combination of the domicile and nationality of each heir and of the deceased; if the deceased lives in Japan (or lived in Japan within the last 10 years), Japanese inheritance tax applies to assets worldwide even if the heir has become a foreign national (Countries without inheritance tax and the 10-year rule, Taxes and resident registration when moving abroad).

The possibility of returning to Japan

For Japanese nationals: after losing Japanese nationality, you need a status of residence as a foreign national to come back and live in Japan. Regaining Japanese nationality requires naturalization in Japan; there are provisions that relax some of the requirements, but approval depends on the examination (Procedures on the Japanese side after acquisition).

Japanese documents required for the application

Applications for naturalization or citizenship by investment abroad often require documents issued in Japan. The main documents and how to obtain them are as follows.

Japanese documents often required in foreign nationality applications (as of October 2026)
Document	How to obtain	Notes
For Japanese nationals: family register certificate (koseki tohon / certificate of all matters)	From the municipality of your registered domicile (by post from abroad). The person concerned and certain family members in Japan can also request it at any municipal counter nationwide (wide-area issuance since March 2024)	Used as proof of birth, marriage and parent–child relationships. An English translation is required
Certificate of criminal record	In Japan, from the prefectural police headquarters where you last lived (the Tokyo Metropolitan Police Department takes about 2 weeks and charges no fee; fees vary by prefecture). From abroad, via a Japanese embassy/consulate, taking about 2–3 months	You apply in person and your fingerprints are taken. A document showing that the receiving authority requires the certificate is needed. Invalid if opened
Apostille / certification of official seal	Ministry of Foreign Affairs (no fee; returned by post in about 3 business days). The Tokyo counter has required appointments since October 5, 2026	Applies to originals of public documents issued within the last 3 months. If the receiving country is a party to the Hague Apostille Convention, an apostille is generally used; otherwise, certification of the official seal plus consular legalization (consular legalization may be required even by some Convention parties)
For Japanese nationals: certificates from Japanese embassies/consulates	Japanese nationals living abroad can obtain certificates of personal status, signature certificates, etc. at Japanese embassies/consulates	Generally only for people holding Japanese nationality. Many certificates are no longer available after nationality is lost

The family register certificate is issued only in Japanese, so in most countries it must be translated and authenticated. Which form of translation and authentication each country and authority requires differs by receiving authority, so checking the receiving authority's guidance first and then gathering the Japanese documents reduces rework. Our office's authentication services (apostille, notarization, etc.) (in Japanese) and family register retrieval from abroad (in Japanese) handle obtaining, translating and authenticating these documents.

Procedures on the Japanese side after acquisition

For Japanese nationals: the procedures required on the Japanese side after acquiring a foreign nationality, and what changes, are as follows.

For Japanese nationals: checklist on the Japanese side after acquiring a foreign nationality
Item	Details
Report of loss of nationality	File with the municipality or a Japanese embassy/consulate within 1 month of learning of the loss (3 months if abroad) (Article 103 of the Family Register Act). A foreign naturalization certificate or similar document must be attached. Failing to file without a justifiable reason is subject to a non-penal fine of up to JPY 50,000 (Article 137 of the Family Register Act)
Japanese passport	Becomes invalid when Japanese nationality is lost (Article 18 of the Passport Act) and must be returned. Using an invalid passport is punishable by imprisonment of up to 5 years or a fine of up to JPY 3 million (Article 23 of the Passport Act)
Entering Japan	Enter on the passport of your new nationality. Whether a visa is required depends on the new nationality (most citizenship-by-investment countries require a visa)
Continuing to live in Japan	You may stay without a status of residence for up to 60 days from the date you lost Japanese nationality. To stay longer, apply for a status of residence within 30 days (Article 22-2 of the Immigration Control Act). The deadline runs from the date nationality was lost, so if you acquired the new nationality while living in Japan, confirm the acquisition date. A person born as the child of a Japanese national (biological child) or the spouse of a Japanese national can apply for "Spouse or Child of Japanese National" (approval depends on the examination)
Pension	Voluntary enrolment in the National Pension available to Japanese nationals living abroad is no longer possible once Japanese nationality is lost. Japanese nationality is not a requirement for receiving the old-age pension; to receive it abroad, notify the Japan Pension Service. Periods of residence abroad after losing Japanese nationality are not counted as "aggregate periods" toward the 10-year eligibility period, so check in advance whether you meet the 10 years
Real estate in Japan	Foreign nationals may own it. From October 5, 2026, a person who newly becomes the registered owner through registration of preservation or transfer of ownership must declare their nationality (a declaration by an existing registered owner whose nationality has changed is optional)
Inheritance procedures	Signature certificates from Japanese embassies/consulates are generally for Japanese nationals. Former Japanese nationals may be able to obtain one for inheritance or the settlement of assets in Japan by presenting an invalidated passport or a removed family register certificate. If not, use a signature certificate from a local notary
Japanese taxes	Without a domicile in Japan, you are a non-resident taxed only on Japan-source income. If you return to live in Japan, you become a resident; a person without Japanese nationality who has lived in Japan for 5 years or less in the past 10 years is treated as a "non-permanent resident"

How to complete the report of loss of nationality and the effect on inheritance if it has not been filed are explained in the section on Article 11 of the Nationality Act in Countries that allow dual citizenship, and the status of residence after losing Japanese nationality in Residence and permanent residence after losing Japanese nationality.

If you acquired a foreign nationality long ago and are unsure whether a report of loss was filed

First obtain the family register certificate (or removed family register certificate) from the municipality of your registered domicile and check whether the loss of nationality is recorded. If it is not, file a report of loss of nationality now with a Japanese embassy/consulate or the municipality (attach your foreign citizenship certificate, etc.; if the deadline has passed, you may be asked for a written statement explaining the delay). Nationality does not affect inheritance rights, so you can inherit your Japanese parents' assets as a foreign national, but if the family register is inaccurate, the inheritance procedures may stall. If you inherit real estate in Japan, registration of the inheritance is mandatory within 3 years of learning that you acquired it by inheritance.

If you want to regain Japanese nationality

To regain Japanese nationality, you apply for naturalization in Japan. From April 2026, ordinary naturalization generally requires at least 10 years of residence, but for former Japanese nationals with a domicile in Japan there is a provision relaxing the requirements such as the number of years of domicile (Article 8(iii) of the Nationality Act). The Ministry of Justice materials do not state how the 10-year practice applies to former Japanese nationals living in Japan.

FAQ

Can I get my spouse's nationality immediately by marrying?

In most countries, marriage alone does not confer nationality; it only shortens the residence required for naturalization. Typical examples are 3 years of residence and settlement in the UK, 3 years after obtaining a green card in the US, and 2 years of residence during the marriage in South Korea. If a foreign law automatically confers nationality upon marriage, a Japanese national does not lose Japanese nationality because they did not apply, but they become a dual national and must choose a nationality within 2 years. In countries where nationality is acquired by declaration (such as France), the declaration also counts as acquisition by one's own choice, and Japanese nationality is lost.

Can I acquire a foreign nationality while living in Japan?

Naturalization through residence requires living in the country, so it cannot be done while living in Japan. Many citizenship-by-investment countries do not require a residence record, so it can be acquired while living in Japan, but a Japanese national loses Japanese nationality on acquisition and needs a status of residence to continue living in Japan.

How long does it take and how much does it cost to acquire a foreign nationality?

Naturalization through residence generally takes 5–10 years or more including obtaining permanent residence, and application fees range from several tens of thousands of yen to over JPY 300,000. Citizenship by investment officially takes about 3–4 months, although some cases take around a year in practice; the donation alone is US$90,000 to US$250,000, plus due diligence fees and professional fees.

What Japanese documents are required for the application?

A family register certificate (for Japanese nationals) and a certificate of criminal record are often required, and translation plus an apostille (or certification of the official seal and consular legalization) is generally needed. A certificate of criminal record applied for from abroad takes 2–3 months, so prepare early.

Can I still receive a Japanese pension after acquiring a foreign nationality?

Japanese nationality is not a requirement for the old-age pension, and a foreign national living abroad can receive it if the eligibility requirements are met. However, voluntary enrolment in the National Pension available to Japanese nationals abroad is no longer possible, and periods of residence abroad after losing nationality are not included in the aggregate periods toward eligibility.

Can I regain Japanese nationality after acquiring a foreign one?

Not automatically. You need to have a domicile in Japan and apply for, and be granted, naturalization in Japan. There are provisions relaxing some requirements for former Japanese nationals, but approval depends on the examination.

Summary: compare the routes, and what you lose, first

There are five ways for a Japanese national to obtain a foreign nationality: naturalization through residence, marriage, descent, investment, and merit, and the most common is naturalization through residence after permanent residence. In 2025–2026, a growing number of countries have tightened their requirements, including Portugal (10 years), Sweden (8 years) and Germany (abolition of the fast track). Whichever route you take, if you apply and acquire the nationality yourself, Japanese nationality is lost at that moment, and you will need to file a report of loss of nationality, return your passport and, if living in Japan, obtain a status of residence. First check whether permanent residence would achieve your goals, and decide taking into account your family's nationality and the possibility of returning to Japan.

Our office provides consultations on relocation abroad, permanent residence and citizenship. We can advise on comparing how to obtain permanent residence or citizenship in your destination, applications for Vanuatu citizenship, preparing a report of loss of nationality, and applying for a status of residence after losing Japanese nationality. We also handle translation of family register certificates and other documents needed for applications, authentication services (apostille, notarization, etc.) (in Japanese) and family register retrieval from abroad (in Japanese) (we do not give tax advice, which is the domain of certified tax accountants). We can assist in English and Japanese.