Complete guide to US dual citizenship. Covers whether the US allows dual citizenship, which countries do and don't allow it, what to do when naturalizing, and practical implications.
The United States does not formally recognize dual citizenship in the sense of having a policy that explicitly endorses it. However, US law does not prohibit US citizens from holding citizenship in another country, and USCIS does not require naturalizing citizens to renounce prior citizenship (though the naturalization oath does include language about renouncing allegiance to foreign states).
The practical result: many US citizens hold dual or multiple citizenships. Foreign nationals who naturalize as US citizens often retain their original citizenship if their home country's laws permit. US citizens who become citizens of other countries generally retain their US citizenship unless they take an affirmative act to relinquish it.
The Supreme Court has strongly protected dual citizenship in Afroyim v. Rusk (1967) and Vance v. Terrazas (1980), holding that US citizenship can only be relinquished voluntarily and with the specific intent to give it up. Merely obtaining a foreign citizenship or swearing allegiance to a foreign state does not automatically forfeit US citizenship.
State Department (DOS) tracks voluntary relinquishment of US citizenship through Form DS-4079 (Request for Determination of Possible Loss of United States Citizenship). DOS must find both the expatriating act (e.g., naturalizing abroad) AND the intent to relinquish US citizenship before issuing a Certificate of Loss of Nationality (CLN).
Many countries do not permit their citizens to hold another country's citizenship. If you naturalize as a US citizen and your home country does not allow dual citizenship, you may automatically lose your original citizenship upon US naturalization.
Countries that generally do not allow dual citizenship (or have significant restrictions): India (though India issues OCI, Overseas Citizenship of India, as a quasi-citizenship that provides permanent residency rights), China, Japan, Singapore, Indonesia, South Korea (with exceptions for those who obtained citizenship at birth), Germany (exceptions for those who would face hardship by renouncing), Austria, Netherlands, and Thailand.
Countries that generally allow dual citizenship: Philippines, Mexico, Italy, Portugal, Ireland, UK, Canada, France, Australia, Israel, Turkey, Colombia, Brazil, and most Caribbean and Latin American countries. Over 50 countries now recognize dual citizenship in some form.
The practical implication: if you're an Indian national naturalizing as a US citizen, India's Citizenship Act requires you to surrender your Indian passport within 3 years of acquiring foreign citizenship. However, you can obtain an OCI (Overseas Citizen of India) card, which grants lifelong multiple-entry visa rights and certain rights in India, though not voting or government employment.
Travel: dual citizens may enter and leave the US using either passport, but US law requires US citizens to enter and exit using their US passport. Using a foreign passport to enter the US as a US citizen is technically a violation, though CBP generally does not pursue this for casual violations.
Taxation: the US taxes its citizens on worldwide income regardless of where they live. This is one of only two countries (the other being Eritrea) that taxes non-resident citizens. US dual citizens living abroad must file US tax returns annually, comply with FBAR and FATCA reporting, and potentially pay US taxes even while paying taxes to their country of residence. This creates complex tax situations requiring international tax specialists.
Military service: dual citizens with citizenship in countries requiring military service may face conscription obligations in those countries. The US government cannot prevent another country from enforcing military service requirements against its own citizens. Some countries (Israel, South Korea, Turkey, Greece, Germany) have military service requirements that could affect US dual citizens.
Government employment and security clearances: dual citizens can obtain US government employment and in many cases security clearances. However, holding citizenship in certain countries (particularly adversarial nations) creates scrutiny in the security clearance process and may disqualify candidates from some classified positions.
The naturalization oath includes: 'I hereby declare, on oath, that I absolutely and entirely renounce and abjure all allegiance and fidelity to any foreign prince, potentate, state, or sovereignty...' This oath language addresses allegiance, not citizenship. USCIS does not require you to renounce the actual citizenship of a foreign country during naturalization.
Whether you retain your foreign citizenship after US naturalization depends entirely on your original country's laws. Some countries automatically strip citizenship upon foreign naturalization (India, China). Others allow you to retain both (Philippines, Mexico, Italy). Research your specific country's rules before naturalizing.
If you wish to retain your original country's citizenship and your country allows dual citizenship with the US: simply naturalize as a US citizen and continue using your original country's passport for travel to that country. Notify the relevant consulate if required by their laws.
If you wish to retain your original country's citizenship but your country does not allow dual citizenship: this is a difficult personal and legal choice. Some people naturalize and quietly maintain their original passport in violation of their home country's rules (risking loss of that citizenship if discovered). Others delay US naturalization. Legal advice tailored to your specific country's laws is essential.
The Overseas Citizenship of India (OCI) is a special immigration status for foreign nationals of Indian origin (and their spouses). OCI is not full Indian citizenship but provides: lifelong multiple-entry visa to India, no need to register with FRRO for stays over 180 days, parity with NRIs for most financial and educational purposes, and ability to purchase non-agricultural property in India.
OCI holders cannot vote in Indian elections, hold Indian government employment, purchase agricultural land in India, or hold certain constitutional offices. They also cannot avail themselves of reservations in educational institutions.
Applying for OCI after US naturalization: submit Form OCI-1A online at the Government of India's Passport Seva portal. Required documents include US passport, surrendered Indian passport, birth certificate, and address proof. Processing takes 3–6 months. OCI cards are processed by the Indian Consulate or Embassy.
The OCI is a good solution for Indian-born US citizens who want to maintain strong ties to India, visit family, invest in property, and retain certain rights in India, even though full Indian citizenship must be surrendered upon US naturalization.
Sarah Chen, Immigration Attorney, has over a decade of experience advising employers and foreign nationals on H-1B petitions, green card sponsorship, and US immigration compliance.