US-Portugal dual citizenship and taxes: What you need to know in 2026
US citizens who hold Portuguese citizenship remain fully liable for US taxes on worldwide income under citizenship-based taxation. Portugal permits dual citizenship without restriction.
The US-Portugal tax treaty and the US Foreign Tax Credit help reduce double taxation in many situations, although dual citizens generally must still file annual US tax returns and meet US reporting requirements – including FBAR and FATCA reporting – regardless of Portuguese tax residency.
For a full breakdown of treaty mechanics, see US-Portugal tax treaty: complete guide for expats.
US-Portugal dual citizenship: key facts (2026)
- Portugal allows dual citizenship with the US – no renunciation required.
- US taxes its citizens on worldwide income regardless of a second citizenship.
- Naturalization generally requires 10 years of legal residence for most non-EU applicants (7 years for EU/CPLP nationals), together with other statutory eligibility requirements under Portugal's Lei Orgãnica 1/2026 nationality law, including language and other legal requirements.
- Transitional rule: nationality applications filed on or before May 18, 2026, are processed under the prior 5-year regime (Lei 37/81).
- Citizenship by marriage: 3 years – following separate statutory rules.
- The Foreign Earned Income Exclusion for tax year 2025 is $130,000 per qualifying person. For tax year 2026, this increases to $132,900.
- FBAR filing is required for Portuguese accounts exceeding $10,000 in aggregate at any point during the year.
- Covered expatriate exit tax thresholds: $2 million net worth or average annual net tax liability above $206,000 (2025). For expatriations in 2026, the tax liability threshold rises to $211,000 (Rev. Proc. 2025-32). Dual citizens who never renounce are never subject to this test.
Does Portugal allow dual citizenship with the US?
Yes. Portugal permits dual and multiple citizenship without restriction. A US citizen who naturalizes in Portugal keeps their US passport automatically – Portugal does not require renunciation of any prior nationality. The United States likewise does not require citizens to renounce US citizenship when acquiring a second nationality.
Three conditions govern dual citizenship recognition for US-Portugal nationals:
- Portugal imposes no renunciation requirement on new citizens.
- The US does not revoke citizenship for acquiring a foreign passport.
- Both countries treat the person as a full citizen for legal and tax purposes simultaneously.
How dual citizenship affects US tax obligations
US citizenship – not residency – determines US tax liability. A dual US-Portugal citizen must file a US tax return every year and report worldwide income, regardless of where they live, how long they have held Portuguese citizenship, or whether they ever set foot in the United States.
The US-Portugal tax treaty and the US Foreign Tax Credit help reduce double taxation in many situations but do not eliminate the annual US filing requirement.
For a broader overview of how the US taxes dual nationals worldwide, see Dual citizenship taxes: US tax rules for dual citizens.
TFX client scenario
A US-Portugal dual citizen working remotely from Lisbon for a US company earned $95,000 in 2025. Portuguese income tax owed: approximately $28,000. In this example, the Portuguese income tax may be sufficient to offset the US federal income tax through the Foreign Tax Credit. Actual results depend on the taxpayer's filing status, income mix, and the foreign tax credit limitation rules. A full US return and FBAR disclosure for the Portuguese bank account are still required. The dual citizenship tax obligations between Portugal and the USA carry real compliance weight even when the final US bill is zero.
Accidental Americans and citizenship by descent
A child born in Portugal to a US citizen parent may acquire US citizenship at birth if the applicable US citizenship transmission requirements are met. If the child is a US citizen, US tax filing and reporting obligations may apply even if the child never lives in the United States.
This scenario – known as "accidental American" status – requires the same annual filing as any other US citizen.
If you are an accidental American who has never filed, you are not alone. The IRS Streamlined Filing Compliance Procedures for accidental Americans allow eligible filers to catch up on 3 years of delinquent returns and 6 years of FBARs without penalty, provided the failure to file was non-willful.
Pro tip: The Streamlined Procedures require a certification under penalty of perjury that your non-compliance was non-willful. If there is any doubt about willfulness, speak with a tax professional before submitting.
Ways to obtain Portuguese citizenship as a US citizen
Portugal's nationality law for 2026 – Lei Orgãnica 1/2026, in force since May 19, 2026 – generally requires 10 years of legal residence for most non-EU applicants and 7 years for EU and CPLP nationals, together with other statutory eligibility requirements, including language and other legal requirements. This is up from the prior 5-year rule under Lei 37/81.
Citizenship by marriage requires 3 years of continuous partnership. Citizenship by descent requires proof of a Portuguese parent or grandparent.
Naturalization under Lei Orgãnica 1/2026 now requires nearly double the residence time that applied before May 19, 2026 – but applications filed on or before May 18, 2026 are still processed under the old 5-year rule.
The residence clock runs from the date the first residence permit is issued. Pending nationality applications filed by May 18, 2026, remain under Lei 37/81, regardless of how long the applicant has lived in Portugal.
If you are considering a move to Portugal, start with Moving to Portugal from the US: complete guide for visa routes, timelines, and cost-of-living data.
Naturalization vs. marriage vs. descent
Portugal grants citizenship through naturalization (7–10 years of residence plus language and knowledge tests), marriage or civil union (3 years), descent, or investment-based residence that starts the naturalization clock.
| Pathway | Residency / time requirement | Key condition |
|---|---|---|
| Naturalization (non-EU) | 10 years of legal residence | A2 Portuguese language test plus the new knowledge test on Portuguese culture, history, and national symbols introduced by Lei Orgãnica 1/2026 |
| Naturalization (EU/CPLP) | 7 years of legal residence | Same language and knowledge tests |
| Marriage or civil union | 3 years of continuous partnership | Proof of declared connection to the Portuguese community |
| Descent | Varies | Portuguese parent or grandparent, documented lineage |
| Golden Visa / investment route | Subject to the naturalization timeline above | Investment alone does not grant citizenship – it provides a residence permit that starts the naturalization clock |
US tax forms that every dual citizen must know
Dual US-Portugal citizens must file Form 1040 annually and report Portuguese financial accounts on FinCEN Form 114 (FBAR) when the aggregate value exceeds $10,000, and on Form 8938 (FATCA) at higher thresholds for those living abroad.
Four forms apply to most US-Portugal dual citizens with foreign income or accounts:
- Form 1040 – annual US income tax return, reporting worldwide income from all sources.
- FinCEN Form 114 (FBAR) – required when the aggregate value of all foreign financial accounts exceeds $10,000 at any point during the year. Filed electronically with FinCEN, not the IRS. The IRS FBAR filing requirements page explains who must file and when.
- Form 8938 (FATCA) – required for foreign assets exceeding $200,000 at year-end or $300,000 at any point during the year (single filers living abroad). Married filing jointly thresholds are $400,000 / $600,000.
- Form 2555 claims the FEIE; Form 1116 claims the Foreign Tax Credit. You can use one or both on the same return, but you cannot apply both benefits to the same item of income.
For a comprehensive walkthrough of each form, see the Tax preparation guide for US expats in Portugal.
FEIE and Foreign Tax Credit for dual citizens
The Foreign Earned Income Exclusion lets qualifying dual citizens exclude up to $130,000 of foreign earned income from US tax for tax year 2025. For tax year 2026, the FEIE limit rises to $132,900.
The Foreign Tax Credit generally allows eligible Portuguese income taxes to offset US tax, subject to the foreign tax credit limitation rules. Many US taxpayers in Portugal eliminate or substantially reduce their US tax, but the result depends on the type of income and individual circumstances.
For many US taxpayers living in Portugal, the Foreign Tax Credit produces a better result because Portuguese income tax rates are often higher than comparable US rates. However, the best choice depends on the taxpayer's income, deductions, and long-term tax situation.
For help choosing between the two, see FEIE vs Foreign Tax Credit: which one should you use. The IRS publishes detailed calculation rules in its guidance on figuring the Foreign Earned Income Exclusion.
Pros and cons of US-Portugal dual citizenship
Dual citizenship between Portugal and the USA carries no added US tax cost by itself, but non-compliance risk is real.
Non-willful FBAR violations carry penalties of up to $16,536 per annual FBAR report – not per account, following the Supreme Court's decision in Bittner v. United States (2023).
Willful violations carry penalties of up to $165,353 or 50% of the account balance, whichever is greater (31 U.S.C. § 5321, 2026 inflation-adjusted amounts).
| Pros | Cons |
|---|---|
| EU passport and visa-free travel to 180+ countries | Permanent annual US filing obligation regardless of residence |
| Right to live and work anywhere in the EU | FBAR/FATCA penalties for non-compliance: up to $16,536 per report (non-willful) or $165,353 / 50% of balance (willful) |
| No renunciation of US citizenship required | No reduction in US tax liability simply from holding a second passport |
The FinCEN Report of Foreign Bank and Financial Accounts page explains reporting obligations in detail.
Renouncing US citizenship instead of holding dual status
Some dual citizens consider renouncing US citizenship to end annual filing obligations. Renunciation triggers exit tax only for covered expatriates – those with:
- Net worth of $2 million or more, or
- Average annual net tax above $206,000 over the prior 5 years (2025). For expatriations in 2026, this threshold rises to $211,000 (Rev. Proc. 2025-32), or
- Unresolved US filing non-compliance (failure to certify 5 years of tax compliance on Form 8854)
US citizens who acquired Portuguese and USA dual citizenship at birth – rather than through naturalization – may qualify for a narrow exit tax exception. This exception applies only if the person:
- Remained a tax resident of Portugal throughout
- Was a US resident for no more than 10 of the last 15 tax years
- Still files Form 8854 certifying 5 years of US tax compliance
For detailed thresholds and planning strategies, see the US exit tax and covered expatriate rules for 2026 and the Form 8854 instructions for 2026.
Bottom line
US-Portugal dual citizenship – what to remember in 2026:
- Portugal allows dual citizenship without renunciation.
- Naturalization now requires 7–10 years of residence under the May 2026 law. Applications filed by May 18, 2026, keep the 5-year rule.
- US taxes its citizens on worldwide income regardless of a second passport.
- FBAR and FATCA apply to Portuguese accounts.
- The FEIE excludes up to $130,000 for tax year 2025 and $132,900 for tax year 2026.
- Renouncing US citizenship avoids future filing but may trigger exit tax for covered expatriates. A narrow exception exists for citizens born with dual nationality.
FAQ
Yes. Both countries permit dual citizenship. Portugal does not require renunciation of any prior nationality when granting citizenship, and the US does not revoke citizenship when a US citizen acquires a foreign passport. You are treated as a full citizen by both countries simultaneously.
Yes. Portugal imposes no restriction on holding multiple citizenships. A US citizen who naturalizes in Portugal retains both passports. The same applies in reverse – a Portuguese citizen who naturalizes in the US keeps Portuguese citizenship.
Under Lei Orgãnica 1/2026 (effective May 19, 2026), naturalization generally requires 10 years of legal residence for most non-EU nationalities, including US citizens, and 7 years for EU and CPLP nationals, together with other statutory eligibility requirements, including language and other legal requirements. Applications submitted to the IRN on or before May 18, 2026, are processed under the prior 5-year rule. Citizenship by marriage follows separate statutory rules and still requires 3 years.
Both countries may tax the same income, but the US-Portugal tax treaty and the US Foreign Tax Credit help reduce double taxation in many situations. In most cases, Portuguese taxes paid can substantially reduce or eliminate your US tax liability, resulting in little or no additional US tax. You must still file a US return every year.
Nothing changes on the US side. Acquiring Portuguese citizenship through marriage does not alter your US tax obligations. You continue filing Form 1040 annually and reporting worldwide income. If you open Portuguese bank accounts, FBAR and FATCA rules apply.
Yes. US law generally permits dual citizenship. The Supreme Court confirmed in Afroyim v. Rusk (1967) that US citizenship cannot be involuntarily revoked. Acquiring a second passport, swearing an oath of allegiance to another country, or serving in a foreign military does not automatically result in loss of US citizenship. Loss of citizenship generally requires a potentially expatriating act performed voluntarily with the intent to relinquish US nationality.
Dual citizenship means you hold full legal citizenship in two countries. Permanent residency means you have the right to live in a country without being a citizen – for example, by holding a Portuguese residence permit (golden visa, D7, or D8). From a US tax perspective, both US citizens and US permanent residents (green card holders) must file annual returns on worldwide income. Portuguese permanent residency alone does not create US filing obligations – only US citizenship or green card status does.
Not necessarily. US citizens who held a second citizenship at birth may qualify for a narrow exception to the covered expatriate rules. To use this exception, the person must have been a tax resident of the other country (Portugal, in this case), must not have been a US resident for more than 10 of the last 15 tax years, and must file Form 8854 certifying 5 years of US tax compliance. The exception is narrow, and a missed Form 8854 can disqualify you.
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