What Is Dual Citizenship? How It Works and How to Get It (2026)

Dual citizenship (or dual nationality) means being legally recognised as a citizen of two countries at the same time, with the rights and obligations of each. You acquire it by birth in a country (jus soli), by descent from a parent (jus sanguinis), by naturalisation, sometimes by marriage, or by citizenship-by-investment. Many countries allow it; some, including China and India, do not.

This is the pillar guide to the whole topic. If you only want the list of jurisdictions, jump straight to our companion piece on countries that allow dual citizenship in 2026, or read on for how the status actually works.

Key Takeaways

• Dual citizenship is simultaneous nationality of two or more states, and each country applies its own rules independently (EBSCO Research Starters, 2026).
• There are five routes in: birth on the soil, descent, naturalisation, marriage and investment (IOM Migration Data Portal, 2026).
• Around 49% of countries fully accept dual citizenship and about 21% restrict it at naturalisation, not the "76%" figure repeated online (GLOBALCIT, 2022).
• Germany's new Nationality Act took effect on 27 June 2024 and now broadly allows dual citizenship (Auswärtiges Amt, 2024).
• China and India forbid it; India's OCI is not citizenship and carries no political rights (Ministry of External Affairs, 2026).
• The EU's last citizenship-by-investment route closed when the Court of Justice ruled against Malta on 29 April 2025 (eucrim, 2025).

What is dual citizenship, and how does it work?

Dual citizenship means a person is recognised as a national of two states at once, holding the full rights and duties of each. The two statuses are independent: each country applies its own nationality law and does not need the other's permission (EBSCO Research Starters, 2026). So you can vote, work and hold a passport in both, and you owe obligations to both.

In practice that independence is the whole point. Your second country cannot strip the first one's citizenship, and the first cannot waive duties you owe the second. Each relationship stands on its own. That is why a person can carry two passports, file two sets of paperwork, and answer to two legal systems without either cancelling the other out.

Dual citizenship vs permanent residence vs a second passport

People mix these up constantly, and the difference is money and rights. Permanent residence lets you live and usually work in a country, but it is not citizenship: you cannot vote, you can lose it by spending too long abroad, and it carries no passport. A second passport is simply the travel document that follows a second citizenship. You cannot hold the passport without first holding the nationality.

Have you ever heard a golden visa sold as a "second passport"? That is the most common sales sleight of hand. A golden visa grants residence by investment, not nationality. We unpack the gap in our guide to what a second passport really is, because the distinction decides whether you can ever travel on the document.

Is there a global register of dual citizens?

No. There is no central international registry of citizenship, and states do not automatically notify each other when they grant or recognise a nationality (OECD, 2026). That said, "no one can find out" is a myth. Financial data now flows across borders under FATCA and the OECD's Common Reporting Standard, so your bank, and your tax authority, can often piece the picture together.

Citation capsule: Dual citizenship is the simultaneous nationality of two or more states, with each country applying its own rules independently, and no central international registry exists (EBSCO Research Starters, 2026). What does cross borders is financial information: FATCA and the OECD Common Reporting Standard share account data between tax authorities, so dual status is rarely truly invisible (OECD, 2026).

How do you get dual citizenship? The five routes

You get dual citizenship through one of five routes: birth on a country's soil, descent from a parent, naturalisation after residence, marriage to a citizen, or citizenship-by-investment (IOM Migration Data Portal, 2026). Which routes are open to you depends on both countries' laws. The same act, taking a second nationality, can be allowed in one place and forbidden in another.

Birth on the soil (jus soli)

Some countries grant citizenship to almost anyone born on their territory, a rule called jus soli, "right of the soil." It is strongest in the Americas, where countries such as the United States, Canada, Brazil and Mexico grant near-automatic citizenship by birth. A child born there to foreign parents can hold the birth country's nationality alongside the parents'. Europe mostly uses conditional versions instead, which we cover in our guide to citizenship by birth and jus soli.

Descent from a parent (jus sanguinis)

Descent, or jus sanguinis ("right of blood"), passes citizenship from parent to child regardless of where the child is born. This is the most common route for people reclaiming a heritage nationality, and several countries, Italy and Ireland among them, let you trace back through grandparents or further. For the documentary detail and the recent tightening in some states, see our piece on citizenship by descent. It is often the cheapest legitimate path to a second passport.

Naturalisation after residence

Naturalisation is the standard route: live legally in a country for a set period, meet language and integration tests, then apply. Residence requirements vary widely. Germany, for instance, cut its requirement from eight years to five under the 2024 reform (Auswärtiges Amt, 2024). The catch is that some countries make you renounce your old nationality to naturalise, which defeats the dual-citizenship goal entirely.

Marriage to a citizen

Marriage rarely grants citizenship outright. Instead it usually shortens the naturalisation clock: a foreign spouse can often apply after a reduced residence period rather than receiving a passport on the wedding day. The rules, and the anti-fraud scrutiny, differ sharply by country, so marriage is best seen as an accelerated naturalisation route, not an instant one.

Citizenship by investment (and the Malta ruling)

Citizenship-by-investment (CBI) grants nationality in return for a qualifying economic contribution, and it has just narrowed sharply. On 29 April 2025 the Court of Justice of the EU ruled in Commission v Malta (Case C-181/23) that Malta's investor-citizenship scheme breached EU law, ending the last citizenship-by-investment route to an EU passport (eucrim, 2025). Existing holders keep their status.

Outside the EU, Caribbean CBI remains open. In March 2024 four of the five Caribbean programmes agreed a harmonised minimum of USD 200,000, but actual country minimums now vary, from Dominica at the USD 200,000 floor up to St Kitts and Nevis at USD 250,000 (Transparency International EU, 2025). These are donation-route figures for a single applicant and exclude due-diligence and processing fees.

Citation capsule: There are five routes to dual citizenship: birth, descent, naturalisation, marriage and investment (IOM Migration Data Portal, 2026). The investment route narrowed in 2025: on 29 April 2025 the Court of Justice of the EU ruled in Commission v Malta (Case C-181/23) that Malta's investor-citizenship scheme breached EU law, ending the last citizenship-by-investment route to an EU passport (eucrim, 2025).

Which countries allow dual citizenship, and which don't?

Most major migration destinations allow dual citizenship, but a meaningful minority restrict or forbid it. The widely shared "76% of countries allow it" claim does not match the data: GLOBALCIT finds roughly 49% of countries fully accept dual citizenship and about 21% consistently restrict it at naturalisation (GLOBALCIT, 2022). The rest sit in between. So always check both of your countries, not just one.

Countries that allow it

The clear "allow" list covers most of the destinations our clients ask about. The United Kingdom, Ireland, Italy, France, the United States, Canada and Australia all permit dual or multiple nationality, as do most EU member states (UK Home Office, 2026). The UK places no restriction at all on holding other nationalities. For the British angle specifically, see our guide to dual citizenship in the UK.

Countries that restrict it with exceptions

A second group tolerates dual citizenship only in narrow cases. Austria restricts it, allowing it mainly by birth, for descendants of Nazi-era victims, or where it serves the Republic's interest. The Netherlands restricts it too, with carve-outs for refugees, spouses of Dutch nationals and birthright dual nationals (Government of the Netherlands, 2026). Japan formally requires dual nationals to choose one nationality by around age 22, though enforcement has historically been light.

One correction worth flagging, because it circulates as fact: the Netherlands has not extended its naturalisation residence period to ten years. A 2025 proposal to lengthen it from five to ten years went to consultation, which closed on 1 December 2025, but it is a proposal, not law (Government of the Netherlands, 2026). Treat any "Netherlands now requires ten years" claim as premature.

Countries that forbid it

A third group does not permit dual citizenship at all. China forbids it: under its Nationality Law, a Chinese national who voluntarily acquires a foreign nationality automatically loses Chinese nationality (National Immigration Administration, 2026). India does not allow it either, and its Overseas Citizen of India (OCI) card is frequently misunderstood. OCI is a long-term visa, not citizenship: it confers no vote and no political rights (Ministry of External Affairs, 2026). Singapore likewise requires renunciation by around age 22.

Did Germany change its law?

Yes, and it is the biggest recent shift in Europe. Germany's new Nationality Act took effect on 27 June 2024: it broadly allows dual citizenship and cut the naturalisation residence requirement from eight years to five (Auswärtiges Amt, 2024). Germans who acquire a foreign nationality no longer lose their German citizenship, and naturalising foreigners may now keep their original one. That moves Germany firmly into the "allow" column.

Citation capsule: Roughly 49% of countries fully accept dual citizenship and about 21% consistently restrict it at naturalisation, not the "76%" figure often quoted (GLOBALCIT, 2022). China and India forbid it, and India's OCI is not citizenship (Ministry of External Affairs, 2026), while Germany's new Nationality Act of 27 June 2024 broadly allows it and cut residence from eight years to five (Auswärtiges Amt, 2024).