Yes, you can be a citizen of both the United States and Portugal at the same time, and hold both passports. Becoming Portuguese does not cost you your American citizenship, and Portugal does not ask you to give up the nationality you already have. For most Americans building a life in Portugal, dual citizenship is the natural end point, not a legal problem to solve.
The rules behind that plain answer sit in two places. The United States permits its citizens to hold another nationality, and Portugal, under its Nationality Law, does not require you to renounce your existing citizenship when you naturalize. The one thing that surprises people most is tax: becoming Portuguese does not switch off your US tax filing, because the United States taxes its citizens on worldwide income wherever they live. This page walks through both sides of the passport, and how the two systems fit together.
Getting help with this The task most American clients actually face is not proving that dual citizenship is allowed, it is timing a Portuguese naturalization application so it fits cleanly with their US tax position. You can absolutely manage the nationality file yourself if you keep organized records. In practice, the advantage of the assisted route is coordinating the Portuguese application with your US accountant, so that becoming Portuguese does not create an avoidable US tax surprise. Roots Global prepares Portuguese nationality applications and coordinates directly with the client's US CPA on the cross-border tax side.
Does the United States allow dual citizenship?
Yes. The United States lets its citizens hold another nationality, and it does not require you to renounce your US citizenship when you become Portuguese. You keep your US passport, and you remain a US citizen with all the rights and duties that carries.
US law recognizes that a person can be a national of two countries at once. Naturalizing in another country as an adult, while intending to keep your US citizenship, does not by itself cause you to lose it (travel.state.gov). The United States does not formally encourage dual nationality as a matter of policy, because it can create competing obligations, but it clearly permits it. Losing US citizenship generally requires a deliberate, formal act of renunciation, covered further down.
The practical takeaway is simple. Choosing to become Portuguese is not, in US eyes, an act of giving up America. You end the process holding two passports, not trading one for the other.
Does Portugal allow dual citizenship?
Yes. Portugal does not require you to give up your current nationality to become Portuguese, so an American who naturalizes keeps US citizenship and gains Portuguese citizenship on top of it. Dual nationality is fully accepted under Portuguese law.
This is set by the Portuguese Nationality Law, which does not impose renunciation of a prior nationality as a condition of naturalization (diariodarepublica.pt). Portugal has taken this open position for decades, which is one reason it is such a common destination for Americans who want an EU passport without surrendering their US one.
How long it takes to reach Portuguese citizenship, and the year-by-year path after the 2026 nationality reform, is a separate question with its own depth. The timeline, the language requirement, and when the clock starts are covered in the Golden Visa citizenship path guide, and the broader picture of relocating is in moving to Portugal from the USA. This page stays on the dual-nationality question itself: whether you can hold both, and what holding both means.
What does US-Portuguese dual citizenship actually mean?
Being a dual citizen means you carry the full rights and obligations of both countries at once. Each passport opens a different door, and each citizenship carries its own duties. Neither one cancels the other out.
The clearest way to see it is side by side. Each citizenship gives you something the other cannot, and each asks something of you in return.
| US citizenship | Portuguese citizenship | |
|---|---|---|
| Where you can live and work | United States | Portugal and the wider EU |
| Freedom of movement | Within the US | Across the EU |
| Voting | US federal and state elections | Portuguese and EU-level elections |
| Tax reach | Worldwide income, for life | Only when you are tax resident in Portugal |
| Passport used to enter | The United States | Portugal and other EU countries |
| Can you keep the other? | Yes | Yes |
For US citizens specifically, the standout line in that table is the tax row, and it is the one most people underestimate. The rest of this guide unpacks it.
How do you become a Portuguese citizen?
There are three main routes to Portuguese citizenship, and most Americans reach it through the first one: naturalization after a period of legal residence. The other two, descent and marriage, apply to narrower groups.
Here are the routes at a high level:
- Naturalization after legal residence. You live in Portugal legally for the required period, meet the language and civic requirements, and then apply. This is the route for anyone who moves on a visa or residence permit and wants to become Portuguese over time. The exact timeline, the A2 Portuguese requirement, and when the residence clock starts changed with the 2026 reform, and are covered in full in the Golden Visa citizenship path guide.
- Descent (by ancestry). Portuguese citizenship can pass through a Portuguese parent, and in some cases a grandparent, subject to registration and evidence rules. If you have a Portuguese-born parent or grandparent, this route may be faster than residence-based naturalization.
- Marriage or civil partnership. Being married to, or in a registered partnership with, a Portuguese citizen for a qualifying period can open a route to nationality, subject to proof of a genuine and continuing connection to Portugal.
Whichever route applies, the dual-citizenship position is the same at the end: you keep your US nationality and add Portuguese nationality. The route affects how you qualify, not whether you can hold both.
Do dual citizens still pay US taxes?
Yes. Becoming Portuguese does not end your US tax filing, because the United States taxes its citizens on their worldwide income no matter where they live. A US-Portuguese dual citizen who lives in Lisbon still files a US federal return every year, on top of any Portuguese obligations.
The rule is set by US law: US citizens and resident aliens are taxed on income from all sources, inside and outside the United States, and must file a return wherever they reside (irs.gov). Two reporting duties travel with that filing: the FBAR, which reports foreign bank and financial accounts over a threshold, and FATCA reporting of certain foreign assets. Both continue for as long as you hold US citizenship.
Double taxation is usually the first worry, and in practice it is manageable. The United States and Portugal have an income tax treaty, and US law offers the Foreign Earned Income Exclusion and the Foreign Tax Credit, which together are designed to stop the same income being fully taxed twice (home.treasury.gov). The mechanics are genuinely complex, and they turn on your specific income and residency, so this is coordination work between your Portuguese and US advisers rather than a do-it-once calculation. The investment-side tax detail for Americans, including how US reporting interacts with Portuguese fund holdings, sits in Golden Visa funds for US citizens, and the residency-tax picture is in US taxes for Americans in Portugal.
One framing note that matters. Roots Global does not provide US tax advice in-house; on the American side we coordinate with your US CPA or give you direct access to a US-tax specialist, so both systems are handled by the right professional.
Which passport do you use, and where?
Use your US passport to enter and leave the United States, and your Portuguese passport to travel and live across the European Union. The general rule for dual citizens is to enter each country on that country's passport, which keeps every border crossing simple.
US citizens are required to use their US passport when entering and leaving the United States, and a Portuguese passport gives you the right to live, work, and move freely within the EU. So a US-Portuguese dual citizen typically carries both and presents whichever one matches the border in front of them.
| Situation | Passport to use |
|---|---|
| Entering or leaving the United States | US passport |
| Entering or living in Portugal or another EU country | Portuguese passport |
| Working anywhere in the EU | Portuguese passport (no visa needed) |
| Seeking consular help in a third country | Whichever country you want assistance from |
| Travelling elsewhere in the world | Either, depending on visa access |
A short checklist for travelling as a dual citizen:
- Carry both passports on international trips, and keep them valid.
- Present your US passport to US border officers, coming and going.
- Use your Portuguese passport for EU entry lanes and to prove your right to reside.
- Check visa requirements for third countries under each passport, and travel on the stronger one for that destination.
On voting, you can take part in elections in both countries as a citizen of each, subject to each country's registration and residency rules. On military and civic duties, US citizenship carries obligations such as Selective Service registration for men within the required age range, while Portugal ended compulsory military service years ago, so day-to-day duties for a dual citizen are light. If any of these ever appear to conflict, that is the point to take specific advice.
Should you renounce US citizenship?
For most people, no. Renouncing US citizenship is a serious, irreversible step that a small number of Americans take, usually for tax reasons, and it is a separate decision from becoming Portuguese. You do not have to renounce anything to hold a Portuguese passport.
Renunciation is a formal act carried out before a US consular officer abroad, not something that happens automatically when you naturalize elsewhere (travel.state.gov). It can also trigger a US expatriation tax, often called the exit tax, which applies to certain higher-net-worth or high-income individuals who give up citizenship (irs.gov).
Because it ends your right to live and work in the United States and can carry a tax cost on the way out, renunciation is a decision to weigh carefully with a US tax adviser, and only after the numbers are clear. For the vast majority of Americans in Portugal, holding both passports is the better answer, and the US tax filing that comes with it is a manageable annual task. The tax side of that choice is covered in US taxes for Americans in Portugal.
See also
- Golden Visa citizenship path for the Portuguese naturalization timeline and when the residence clock starts.
- moving to Portugal from the USA for the full relocation picture for Americans.
- Golden Visa funds for US citizens for how US tax reporting interacts with Portuguese investments.
- US taxes for Americans in Portugal for the residency-tax and double-tax detail.
Frequently asked questions
Does the US allow dual citizenship with Portugal? Yes. The United States permits dual nationality, so you can be a citizen of both the US and Portugal at the same time. Naturalizing in Portugal as an adult, while intending to keep your US citizenship, does not by itself cause you to lose it, and you keep your US passport (travel.state.gov).
Will I lose my US citizenship if I become Portuguese? No. Losing US citizenship generally requires a deliberate, formal act of renunciation before a US consular officer. Simply becoming Portuguese does not strip your US nationality, and Portugal does not ask you to renounce it either. You end up holding both passports rather than trading one for the other.
Do dual citizens pay US taxes? Yes. US citizens file US federal tax on worldwide income for as long as they hold citizenship, wherever they live, so becoming Portuguese does not end US filing (irs.gov). FBAR and FATCA reporting continue, and the US-Portugal treaty plus the Foreign Earned Income Exclusion and Foreign Tax Credit limit double taxation.
Which passport do I use to travel? Enter and leave the United States on your US passport, and use your Portuguese passport to enter, live, and work across the EU. The general rule for dual citizens is to present each country's passport at that country's border. Carry both when you fly internationally, and keep both valid.
Can I vote in both countries? Yes. As a citizen of each country you can take part in its elections, subject to each country's registration and residency rules. US citizens abroad can generally vote in US federal elections, and Portuguese citizens can vote in Portuguese and EU-level elections.
Does Portugal require me to give up my US citizenship? No. Portuguese nationality law does not require you to renounce a prior nationality, so an American who naturalizes keeps US citizenship and gains Portuguese citizenship on top of it (diariodarepublica.pt). Portugal has accepted dual nationality for decades.
How do I actually become a Portuguese citizen? Most Americans reach citizenship by naturalizing after a period of legal residence, meeting a language and civic requirement. Citizenship can also pass by descent through a Portuguese parent or grandparent, or through marriage or a civil partnership with a Portuguese citizen. The residence-based timeline is covered in the Golden Visa citizenship path guide.
Is it worth renouncing US citizenship for tax reasons? For most people, no. Renunciation is a serious, irreversible consular act that can trigger a US expatriation (exit) tax for certain higher-income or higher-net-worth individuals (irs.gov). Holding both passports and filing the annual US return is the better answer for the large majority of Americans in Portugal.
Disclaimer
This article is for general information only and is not legal or tax advice. Nationality, immigration, and tax rules change, and US and Portuguese tax obligations interact in ways that depend on your personal situation, so verify current requirements with the relevant authority or a qualified professional before acting. Last updated: July 2026.
About the author
Vanessa Mororó is Head of Legal, Portugal at Roots Global, where she advises HNWI and US cross-border clients on Portuguese nationality, residency, and immigration matters, including dual US-Portuguese citizenship and the path to a Portuguese passport. Connect on LinkedIn.
