Citizenship Guides
Which countries allow dual citizenship in 2026? US, UK, Canada, France, Germany, Spain, Sweden, Denmark, plus what you must renounce when naturalizing.
Dual citizenship determines whether you can hold two passports without giving up either, or whether naturalizing in your new country means formally renouncing your birth nationality. The rules are set independently by each country, which creates a matrix problem: you need to check what the country you're naturalizing into requires, and what your country of origin permits. This guide covers both sides for the most common combinations.
Among the eight countries covered by CivicPass, the policies differ materially:
The US does not restrict its citizens from holding another nationality, and it does not require applicants to renounce a foreign nationality as a condition of naturalization. The naturalization oath includes language about renouncing "allegiance and fidelity" to foreign states, but this is interpreted as an oath of loyalty rather than a legal requirement to formally surrender another passport. In practice, most naturalized US citizens retain their original nationality if their birth country allows it.
Important caveat: the US taxes its citizens on worldwide income regardless of where they live, and this applies to dual citizens. Holding US citizenship while residing abroad creates annual FBAR and FATCA reporting obligations.
The UK permits dual nationality. British subjects are not required to renounce a foreign citizenship upon naturalization, and existing British citizens are not required to surrender their passport if they acquire another nationality. This is one of the more open policies among large countries.
Canada explicitly allows dual and multiple citizenship. There is no requirement to renounce a foreign nationality upon naturalization, and Canadian citizens may acquire additional nationalities without losing Canadian status. Canada has allowed dual citizenship since 1977.
France does not require renunciation of a foreign nationality as a condition of naturalization. However, some bilateral treaties between France and other countries affect how dual nationality is treated, particularly for older treaty partners. For most applicants, dual French-other citizenship is straightforward. French law requires that French citizens use their French passport when entering and leaving France.
Spain generally allows dual nationality. Nationals of Ibero-American countries (Latin America, Equatorial Guinea, Philippines, Andorra, and Portugal) can naturalize in Spain without renouncing their original citizenship under historical bilateral treaties. For other nationalities, Spain formally requires renunciation of the prior nationality upon naturalization, though enforcement is inconsistent and Spain cannot actually compel another country to recognize the renunciation. Some applicants from non-treaty countries effectively retain dual nationality in practice, though this depends on how their birth country treats the renunciation declaration.
Sweden has allowed dual citizenship since 2001. There is no renunciation requirement for naturalization, and Swedish citizens may acquire additional nationalities without any restriction. Sweden is among the more permissive European countries on this point.
Denmark changed its policy in 2015 to allow dual citizenship. Applicants no longer need to renounce their original nationality to naturalize in Denmark. Existing Danish citizens who had previously renounced another nationality to satisfy the old requirement could apply to regain it under transitional rules. The policy shift has made Danish naturalization significantly more accessible for those whose birth countries also allow dual nationality.
Germany has historically required renunciation of other nationalities upon naturalization, with notable exceptions for EU citizens, recognized refugees, and those for whom renunciation is impossible or involves unreasonable hardship. In 2024, Germany reformed its nationality law (Staatsangehörigkeitsgesetz) to substantially broaden access to dual citizenship, including for most naturalization candidates. As of 2024, Germany's default position moved toward accepting dual nationality, though the details of the reform and its application to specific cases are worth verifying with the relevant Einbürgerungsbehörde.
Even if your new country permits dual nationality, your birth country may not. If your birth country requires you to give up your original citizenship when you naturalize elsewhere, you face a real decision. Countries that generally prohibit their nationals from holding dual citizenship include:
The safest approach is a two-step check:
The embassy check matters because laws change. Germany's 2024 reform is a recent example, anyone relying on information from a few years ago would have received incorrect guidance. For significant legal decisions like renouncing a nationality, verify with an official source or an immigration attorney familiar with both countries' laws.
When renunciation is required, the process typically involves a formal declaration at the consulate or embassy of the country being renounced, sometimes with a waiting period and a fee. The US, for example, charges $2,350 to renounce US citizenship, one of the highest fees in the world. Renunciation is generally irrevocable; there is no standard process to regain a citizenship you've formally surrendered.
If you're going through naturalization and dual citizenship is uncertain in your situation, understanding your complete rights and obligations is worth the time before you begin the formal process. Our guide on permanent resident vs. citizen covers the broader question of whether and when naturalization makes sense for your specific circumstances. Once you've confirmed dual citizenship is viable, prepare for the knowledge test with free mock practice questions: US · Canada · UK · Germany · France · Spain · Sweden · Denmark.