Dual Citizenship Rules: How You Can Lose Your First Passport

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An open and a closed passport beside a passport renewal form

Dual citizenship rules vary widely. See which countries allow it, which restrict it, and how a second passport can cost you your first citizenship.

Key takeaways

  • Your original country's law decides whether you keep its citizenship. The country granting your new passport has no say in it.
  • In countries such as Austria, India, China and Japan, voluntarily acquiring another citizenship can end the original one automatically, without any notice.
  • Where permission is needed, as in Austria or Saudi Arabia, it has to be in place before you acquire the second citizenship.
  • Germany (2024), Brazil (2023) and Ukraine (2026) have relaxed their rules recently, so advice from a few years ago may be out of date.
  • A second citizenship can also affect your children, military obligations, consular protection and tax.

Illustrative scenario: the person and details below are invented to show how these rules work in practice.

Thomas is Austrian and has run a trading company from Dubai since 2019. In 2022 he acquired a Caribbean citizenship through an investment programme, mainly to make travel to a few markets easier and to open a second banking relationship. The process went smoothly, the passport arrived after a few months, and nobody involved asked him about Austria. Four years later his Austrian passport is about to expire, so he books an appointment at the Austrian embassy in Abu Dhabi. There he learns that under Austria's dual citizenship rules he stopped being Austrian on the day his second citizenship was granted, because he never applied for permission to keep it.

The passport is the smallest part of the problem. Without Austrian citizenship he no longer has an automatic right to live and work in Austria or anywhere else in the EU, so his plan to spend summers in Salzburg and eventually retire there now depends on a residence permit. His daughter, born in Dubai in 2023, was born after he lost his citizenship and did not acquire it through him. Austria only grants a retention permit before the foreign citizenship is acquired, so there is nothing to apply for retrospectively. Regaining citizenship is possible in some situations, but it is slow and the outcome is uncertain.

Situations like this happen because most people research the rules of the country they are joining and never look at the rules of the country they come from. This article covers how countries approach dual citizenship, which countries allow it and which restrict it (as of October 2026), the less obvious effects on family, military service, consular help and tax, and what to check before you apply anywhere. It is general information. How the rules apply to you depends on your nationality, how you acquire the second citizenship and your family situation, and needs to be checked for each case.

What are dual citizenship rules, and why do they differ so much?

Dual citizenship rules are the parts of each country's nationality law that decide whether its citizens may hold another nationality at the same time, and every country writes its own. There is no international standard. Each state decides who its own citizens are and has no say over anyone else's citizens. That leads to the point most people miss: the country giving you a new passport cannot protect your old one. Switzerland's migration authority is open about this. Swiss law has no problem with you keeping your previous nationality, but whether you actually keep it depends on your country of origin, and the Swiss authorities refer you to that country's consulate for the answer.

Countries broadly take one of three approaches.

Fully allowed. You can acquire another citizenship without asking anyone and keep your own. The UK, the United States, Canada, France, Ireland, Italy and Switzerland have worked this way for years, and Germany joined them in 2024.

Allowed only with permission or in exceptions. Dual citizenship is possible, but only with prior approval, a declaration within a deadline, or under specific exceptions. Austria, the Netherlands, Spain and Saudi Arabia are in this group, each with different mechanics.

Not allowed. Acquiring another citizenship by your own choice ends your original one, either automatically by law or because the authorities withdraw it. India, China, Japan, Singapore, Indonesia, Malaysia and South Korea are examples. The UAE sits here too, although since 2021 investors and selected specialists granted Emirati nationality have been allowed to keep their existing citizenship.

The key word in most restrictive systems is "voluntary". Loss is typically triggered when you apply for and accept another nationality, as with naturalisation after years of residence or citizenship by investment. A citizenship you receive automatically, for example at birth, is often treated differently. That distinction becomes important for children, as you'll see below.

Which countries allow dual citizenship?

Most Western countries now allow dual citizenship, and the list has grown over the past decade. If you are a citizen of the UK, the United States, Canada, Ireland, France, Italy, Switzerland or Mexico, acquiring a second citizenship does not put your first one at risk under your own country's law. The US State Department states that Americans can naturalise abroad without risking their US citizenship. Mexico's constitution goes further: a Mexican by birth cannot be deprived of their nationality at all.

Being allowed only describes your side of the arrangement. Your home country may accept dual citizenship while the country you are joining requires you to give up every other nationality, or the reverse. You need both answers.

Which countries have changed their dual citizenship rules recently?

Several countries have relaxed their rules in the past few years, so advice you received earlier may now be wrong in either direction.

Germany is the biggest change. Since 27 June 2024, Germans no longer lose their citizenship when they acquire a foreign one, and people naturalising in Germany no longer have to give up their previous nationality. The provision that caused the loss was repealed, so the retention permit (Beibehaltungsgenehmigung) that Germans used to need before taking another citizenship is no longer required.

Brazil amended its constitution in October 2023. Acquiring another nationality no longer costs Brazilians their own. Loss now requires an express request, and that request cannot be granted if it would leave the person stateless.

Norway has allowed dual citizenship since 1 January 2020, but the change was not retroactive. Norwegians who took another citizenship before 2020 lost their Norwegian citizenship at the time, although they may be able to reclaim it. Norwegians who acquire a new citizenship today must inform the Norwegian authorities in writing, which is easy to overlook.

Ukraine's law on multiple citizenship came into force on 16 January 2026. It allows Ukrainians to keep their citizenship when acquiring another one under defined conditions, and excludes states classed as aggressors. Implementation is still developing, so the details should be confirmed with Ukrainian authorities before anyone relies on them.

Which countries do not allow dual citizenship, or only with permission?

Countries that do not allow dual citizenship are concentrated in Asia and the Gulf. The permission group includes several European countries that many people assume are relaxed. The table below shows a selection across regions. Treat it as a guide to which questions to ask, not as a replacement for checking the law that applies to you.

Dual citizenship rules in selected countries (as of October 2026)

Country Approach What happens if you voluntarily acquire another citizenship
Germany Allowed No effect; dual citizenship accepted since 27 June 2024
United Kingdom Allowed No effect; no application needed
United States Allowed No effect; a US passport is still required to enter and leave the US
Canada Allowed No effect; a Canadian passport is needed to fly back to Canada
Ireland Allowed No effect
Switzerland Allowed No effect (since 1992)
Italy Allowed No effect unless you formally renounce (since 1992)
Brazil Allowed No effect since October 2023
Mexico Allowed Mexicans by birth cannot be deprived of their nationality
Norway Allowed, with notification Citizenship kept (since 2020); authorities must be informed in writing
Ukraine Allowed under conditions Since 16 January 2026, citizenship can be kept under defined conditions; aggressor states excluded
Austria Only with prior permission Automatic loss unless a retention permit was granted before acquisition
Netherlands Only in exceptions Generally lost; exceptions include being born and living in that country, or acquiring a spouse's nationality
Spain Declaration required Spaniards living abroad lose it after three years unless they declare they want to keep it; some countries exempt (see below)
Saudi Arabia Only with prior permission Prime Minister's permission required; acquiring without it is grounds for revocation
South Korea Not allowed (voluntary acquisition) Korean nationality lost on voluntary acquisition; limited options for involuntary cases
Japan Not allowed Lost on acquiring a foreign nationality by choice; dual nationals from birth must choose
China Not allowed Lost automatically for nationals settled abroad who naturalise elsewhere
India Not allowed Citizenship ends on voluntary acquisition; OCI status is not dual citizenship
Singapore Not allowed for adults Dual citizens must renounce foreign citizenship by age 21 to keep Singapore citizenship
Indonesia Not allowed Lost on acquiring another nationality voluntarily
Malaysia Not allowed Citizenship can be removed under Article 24 of the Federal Constitution
UAE Not allowed, with exceptions Federal Law No. 17 of 1972 provides for withdrawal of citizenship; since 2021, investors and selected specialists granted Emirati nationality may keep their existing one
Qatar Not allowed Nationality may be withdrawn by Emiri decision

Three entries in the middle group are worth a closer look, because each fails in a different way.

Spain doesn't ask for permission in advance. Instead, a Spaniard living abroad who voluntarily takes another nationality has three years to declare at the Civil Registry or a consulate that they want to keep Spanish nationality. If the deadline passes without that declaration, the nationality is lost. Acquiring the citizenship of an Ibero-American country, Andorra, the Philippines, Equatorial Guinea or Portugal does not trigger this rule.

The Netherlands generally takes Dutch citizenship away from adults who voluntarily acquire another one, with three exceptions: you were born in the other country and live there; you lived there for at least five continuous years as a minor; or you acquired your spouse's or partner's nationality. Because of a treaty with Austria, the exceptions don't apply when a Dutch citizen becomes Austrian. Mixed Dutch-Austrian couples who assume the spouse exception protects them are caught by this.

Saudi Arabia requires prior permission from the Prime Minister. Acquiring another nationality without it is grounds for revocation, and the consequences reach well beyond travel documents. After written notice, property can be liquidated under the real estate ownership rules, and the person can be barred from living in or returning to the Kingdom.

Can you lose your citizenship by acquiring another without realising it?

Yes. In countries with automatic loss, citizenship ends by operation of law on the day the new one is granted. There is no letter, no hearing and no confirmation, and you usually find out only when you next deal with your home country's authorities.

Automatic loss happens without any notice

Your old passport stays in the drawer looking perfectly valid, and that is the trap. India is a clear example. An Indian who voluntarily becomes a citizen of another country ceases to be Indian at that moment, and continuing to hold or travel on an Indian passport afterwards is an offence under the Passports Act 1967. The status available to former Indians, Overseas Citizenship of India (OCI), is explicitly not dual citizenship. It gives no voting rights and does not allow the purchase of agricultural or plantation land, which matters to families who expect to inherit farmland.

Some countries also end citizenship through absence rather than acquisition. Indonesians who live abroad for five continuous years can lose their citizenship if they don't declare that they want to keep it. Dutch adults who live outside the Netherlands and the EU for more than 13 years while holding another nationality lose their Dutch citizenship if they don't renew their Dutch passport or obtain a declaration of nationality within that period.

Permission has to come before the application

Where permission is possible, it almost always has to be in place before you acquire the second citizenship. Austria is strict on this point. You apply in writing to the provincial government (or through an Austrian embassy if you live abroad), wait for the written decision, and only then take the foreign citizenship. Approval is not automatic. It requires grounds such as a special interest of the Republic, or particularly relevant private or family reasons, which are open only to Austrians who acquired their citizenship by descent. A permit also lapses if the foreign citizenship is not acquired within two years. If you reverse the order, there is nothing left to approve.

Your children may inherit the problem

A parent's loss of citizenship can determine what their children receive. A child born after the loss, like Thomas's daughter, cannot acquire citizenship through that parent. Children who are dual nationals from birth face their own deadlines in several countries. Japan requires dual nationals to choose one nationality by a set age (by 20 if the second nationality was acquired before 18). Singapore requires renunciation of the foreign citizenship by 21, and Indonesia expects a choice once the child is 18 or married. Austria, by contrast, lets children who receive another citizenship automatically at birth keep both without any declaration.

Rules on citizenship by descent can also change. Italy tightened its rules in 2025, so children born abroad who hold another citizenship no longer automatically become Italian by descent unless specific conditions about their parents or grandparents are met. Families who expected the next generation to inherit an Italian passport may need to plan differently.

Military service doesn't disappear with a second passport

Some countries can require their citizens to perform military service even if they live abroad and hold another passport. Canada's official travel advice warns that dual citizens can be required to register for military service in their other country of nationality, sometimes on arrival or when trying to leave. South Korea links nationality matters closely to service obligations for men of military age, and Singapore can withhold renunciation of citizenship until national service obligations are settled. Parents of sons need to consider this before passing on a second citizenship.

Consular protection has limits

Your second passport won't help you much in the country of your first. The UK government states that it cannot give diplomatic help to a British dual national while they are in their other country of nationality, so a British-French citizen in France is treated as French. The US and Canada say much the same. For anyone holding a citizenship that comes with legal or political risk, this is a real limitation.

Some citizenships come with a tax bill wherever you live

The United States taxes its citizens on their worldwide income regardless of where they live. A US citizen living in Dubai, where there is no personal income tax, still has US filing obligations. Relief such as the foreign earned income exclusion and foreign tax credits can reduce the amount owed, but the obligation to file remains. This affects people who were born in the US or to a US parent as much as those who naturalise. Anyone considering a citizenship that is taxed this way should understand the long-term administrative and tax cost before applying.

What should you check before applying for a second citizenship?

Before applying for a second citizenship, check the law of every country whose passport you hold today, not only the rules of the new country. These are the questions worth having answered in writing:

  • Does my current country allow dual citizenship, and does the way I'm acquiring the new one (naturalisation, investment, descent, marriage) count as voluntary?
  • Do I need permission before I apply, or a declaration within a deadline afterwards?
  • Do I need to notify my current country after acquiring the new citizenship?
  • Does the new country require me to renounce my existing citizenship?
  • What happens to children born before and after the new citizenship is granted?
  • Are there military service obligations in either country for me or my children?
  • Does either citizenship bring tax filing obligations that don't depend on residence?
  • Would losing my original citizenship affect property, inheritance or residence rights that matter to my family?

The answers depend on how your citizenship, residency, tax residence and family situation fit together, which is why GWS looks at these questions together rather than in isolation and works with qualified legal partners on the nationality law itself.

Who this is for, and who it isn't for

This article is for you if you are considering a second citizenship through investment, naturalisation or descent and hold a passport from a country that restricts dual nationality, or if you are unsure which category your country falls into. It is also relevant if you already acquired a second citizenship some years ago and never checked how your home country treated it. That is when finding out sooner is better than finding out at an embassy counter.

It is less relevant if both your current and your intended citizenship clearly allow dual nationality and neither brings tax or military obligations, for example a British citizen naturalising in Ireland. It is also not a substitute for legal advice on your specific case. Nationality law is applied strictly, the details turn on dates and individual facts, and a short consultation with a lawyer qualified in your country's nationality law is worth far more than any general overview.

What matters most before you add a second passport?

The decision comes down to a small number of points. First, find out which of the three approaches your current country takes and whether your planned route counts as voluntary acquisition. Second, if permission or a declaration is required, find out the exact sequence and deadlines, because in most systems a missed step cannot be fixed afterwards. Third, look beyond your own passport: children, military service, consular protection and tax all depend on which citizenships the family holds.

That completes this series. It began with the four routes to a second citizenship, and the overall conclusion is that the route you choose matters less than the order in which you do things. Investment programmes come with their own costs and due-diligence demands, and a residency is sometimes the more proportionate answer to the problem you are actually trying to solve. Whichever route you take, checking whether you can keep the citizenship you already have should be the first step, not the last.

The second citizenship series

FAQ

Which countries do not allow dual citizenship?

As of October 2026, examples include India, China, Japan, Singapore, Indonesia, Malaysia, South Korea, the UAE and Qatar, where voluntarily acquiring another citizenship ends or can end your original one. Austria and Saudi Arabia allow it only with prior permission.

Can you lose your citizenship by acquiring another without being told?

Yes. In countries with automatic loss, citizenship ends by law on the day the new one is granted, with no notification. Many people only find out when they try to renew a passport.

Does citizenship by investment count as voluntary acquisition?

In most restrictive systems, yes. You apply for it and accept it, so it is generally treated the same as naturalisation. Whether that applies to you should be confirmed under your own country's law before you apply.

Which countries allow dual citizenship after recent reforms?

Germany has allowed it since 27 June 2024, Brazil since October 2023 and Norway since January 2020. Ukraine allows it under defined conditions since 16 January 2026.

Can I get my original citizenship back after losing it?

Sometimes. Some countries offer reacquisition routes, for example Norway for those who lost citizenship before 2020. Others treat you like any foreigner applying to naturalise, so the answer depends entirely on the country.

Want to know more?

If you're considering a second citizenship and want to understand how it fits with your current passport, residency and family situation, you're welcome to book a call with our team.

Sources

About Global Wealth Strategy

Global Wealth Strategy (GWS) is an independent international advisory firm based at the Dubai World Trade Centre. Founded in Germany in 2018 and now headquartered in Dubai, GWS helps entrepreneurs, investors, high-net-worth individuals and families bring structure to their international lives: from company structuring and banking to asset protection, real estate, residency and succession. Every engagement starts with a clear roadmap across the areas that matter for the client, and GWS can implement it end to end. Our advisory is fee-based and independent, and we work alongside specialist legal and tax partners to turn complex cross-border situations into clear, coordinated strategies.

Disclaimer: This article is for general information only and does not constitute legal, tax or financial advice. Rules and requirements change, and outcomes depend on individual circumstances. Please seek qualified professional advice before acting.

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