Dual Citizenship Guide

Dual citizenship, also called dual nationality, means that a person is simultaneously recognized as a citizen of two different countries. Each country considers the individual a full national, entitled to the rights and subject to the obligations of citizenship in that jurisdiction. A dual citizen holds two passports, can live and work freely in both countries, and is entitled to consular protection from either government while traveling abroad.

Dual citizenship can arise in several ways. A child born in a country that grants citizenship by birth (jus soli) to parents who are nationals of a country that grants citizenship by descent (jus sanguinis) may automatically hold both nationalities from birth. It can also result from naturalization, when a person becomes a citizen of a new country without being required to renounce their original nationality. Marriage to a foreign national can open a pathway to a second citizenship in some jurisdictions as well.

There is no single international law governing dual citizenship. Each country sets its own rules about whether it recognizes, tolerates, or prohibits holding a second nationality. The legal implications, from taxation to military service, depend entirely on the specific laws of both countries involved.

The global landscape on dual citizenship is complex and varies significantly from one country to another. Most Western democracies permit dual nationality, while several Asian and some other nations prohibit it outright.

Countries that broadly allow dual citizenship include the United States, the United Kingdom, Canada, Australia, France, Italy, Ireland, Portugal, Sweden, and most of Latin America. These countries generally do not require citizens to renounce a foreign nationality when they naturalize, nor do they revoke citizenship from nationals who acquire a second passport. The US, for example, has recognized dual citizenship since the Supreme Court's 1967 ruling in Afroyim v. Rusk, holding that a citizen cannot be involuntarily stripped of their nationality.

Countries that prohibit dual citizenship take the opposite approach. Japan requires citizens who acquire a second nationality to choose one by age 22 (or within two years of acquiring the second citizenship). India does not allow dual citizenship at all, though it offers an Overseas Citizen of India (OCI) card that provides some residency and travel benefits without full nationality. Indonesia, China, and Singapore similarly require citizens who naturalize elsewhere to renounce their original citizenship.

Germany is a notable case of recent change. Historically, Germany required naturalization applicants to renounce their existing citizenship. However, a major reform effective June 2024 eliminated this requirement, allowing dual citizenship for all naturalization applicants. This brought Germany in line with most of its European neighbors.

Other countries fall into a middle ground. South Korea prohibits dual citizenship for most adults but allows it for certain categories, including ethnic Koreans returning from abroad. The Philippines does not allow dual citizenship by default but enacted the Dual Citizenship Act of 2003, permitting natural-born Filipinos who naturalized elsewhere to re-acquire Filipino citizenship.

Before pursuing a second nationality, always check the current laws in both countries involved to ensure neither will force a renunciation.

There are several recognized pathways to acquiring a second citizenship, and the best option depends on your personal circumstances and the countries involved.

Naturalization while retaining your original citizenship is the most common route. If both your current country and your target country allow dual nationality, you can go through the standard immigration process — obtain a visa, become a permanent resident, meet the residency requirements, and apply for citizenship without renouncing. Countries like the US, Canada, UK, and Australia follow this model.

Citizenship by descent allows individuals to claim nationality through a parent, grandparent, or in some cases a more distant ancestor. Italy, Ireland, Poland, Hungary, and several other countries have generous descent-based citizenship laws. Italian citizenship by descent (jure sanguinis), for example, has no generational limit, provided the chain of Italian citizenship was never broken by voluntary renunciation. Irish citizenship can be claimed through a grandparent with a registration process.

Citizenship by investment programs grant nationality in exchange for a significant financial contribution to the country. Programs in Malta, Turkey, Jordan, and several Caribbean nations (St. Kitts and Nevis, Dominica, Grenada) offer citizenship for investments typically ranging from $100,000 to $1,000,000 or more. These programs have faced increasing international scrutiny and may affect visa-free travel arrangements.

Citizenship through marriage is available in some countries on an accelerated timeline. Spain, for instance, reduces its residency requirement from ten years to one year for spouses of Spanish citizens. Brazil and Italy also offer shortened paths for spouses.