Dual nationality by country
Last reviewed: 9 October 2026
Whether naturalisation requires giving up another nationality, and whether acquiring a foreign nationality causes loss of the home nationality. Pick a country for the full list of rules, each with its official source.
| Country | Naturalisation: giving up the previous nationality | Naturalisation: exceptions to giving up the previous nationality | Voluntarily acquiring a foreign nationality | Loss of nationality on acquiring a foreign nationality: details |
|---|---|---|---|---|
| Germany | Not required | None needed: the requirement to give up the previous nationality no longer exists. | No loss | Acquiring a foreign nationality is no longer a ground for losing German nationality: the former § 25 is repealed. |
| Netherlands | Required, with exceptions | The application is refused if the applicant has not done what is possible to lose the other nationality, unless this cannot reasonably be required. The requirement does not apply to nationals of certain treaty states (Article 9(3)(a)), to people born in the Netherlands, Aruba, Curaçao or Sint Maarten who live there, to people married to a Dutch national, or to recognised refugees. | Loss, with exceptions | An adult loses Dutch nationality by voluntarily acquiring another nationality. This does not apply to a person born in that country who lives there when acquiring it, to a person who lived there for at least five uninterrupted years before turning 18, or to a person married to a national of that country. |
| United Kingdom | Not required | None needed: dual citizenship is allowed in the UK. | No loss | A British citizen who acquires another nationality keeps British citizenship. Giving it up requires a declaration of renunciation under section 12 of the British Nationality Act 1981. |
| France | Not required | None needed: French law does not require a foreigner who becomes French to give up their nationality. | Only if you declare it | An adult French national living habitually abroad who voluntarily acquires a foreign nationality keeps French nationality unless they expressly declare that they want to lose it. The declaration can be made from the filing of the foreign application until one year after the acquisition. |
| Spain | Required, with exceptions | Exempt are nationals of the countries named in Article 24(1) (Ibero-American countries, Andorra, the Philippines, Equatorial Guinea and Portugal) and Sephardim of Spanish origin. | Loss if resident abroad, unless declared | Emancipated Spanish nationals who habitually reside abroad and voluntarily acquire another nationality lose Spanish nationality after three years, unless they declare before the Civil Registry that they wish to keep it. Acquiring the nationality of an Ibero-American country, Andorra, the Philippines, Equatorial Guinea or Portugal does not by itself cause this loss. |
| Italy | ⚠ Not yet verified | ⚠ Not yet verified | No loss | A citizen who holds, acquires or regains a foreign citizenship keeps Italian citizenship, but may renounce it if resident, or establishing residence, abroad. |
| United States | ⚠ Not yet verified | Every applicant takes an oath to renounce and abjure absolutely and entirely all allegiance and fidelity to any foreign state of which they were a subject or citizen. The oath may be modified for religious or conscientious reasons (affirmation, no bearing of arms) and may be waived for an applicant who cannot understand it because of a disability or impairment. An applicant with a hereditary title or noble rank must also renounce it. | ⚠ Not yet verified | A US national, by birth or naturalisation, loses nationality by obtaining naturalisation in a foreign state on their own application after the age of 18 only if they do so voluntarily and with the intention of relinquishing US nationality. The person claiming that loss occurred must prove it by a preponderance of the evidence; the act is presumed voluntary, and the presumption can be rebutted. |
| Canada | Not required | None needed: the grant requirements in section 5(1) do not include giving up another citizenship, and the government states that Canada allows dual citizenship. Whether the applicant's other country lets them keep its citizenship is a matter for that country. | No loss | A Canadian citizen cannot cease to be a citizen except as Part II of the Citizenship Act provides. Acquiring another citizenship is not a ground. A citizen may renounce on application if they hold, or will acquire, another citizenship, are an adult, do not reside in Canada and understand the consequences; citizenship may also be revoked for fraud or false representation. |
| Mexico | Required | Article 19 sets no exception: a foreigner who wishes to naturalise must expressly renounce the nationality attributed to them and all submission, obedience and fidelity to any foreign state (Article 17). The Secretaría can require this only after it has decided to grant nationality, and the naturalisation letter is issued once the renunciations are verified. | Naturalised only | No Mexican by birth can be deprived of their nationality (Article 37(A)). Mexican nationality by naturalisation is lost by voluntarily acquiring a foreign nationality, by passing oneself off as a foreigner in a public instrument, by using a foreign passport, by accepting or using noble titles that imply submission to a foreign state, or by residing abroad for five continuous years (Article 37(B)); loss is declared after a hearing (Ley de Nacionalidad, Art. 27). |
| Ireland | Not required | None needed: Irish law does not require an applicant for naturalisation to give up another citizenship. | No loss | An Irish citizen who acquires another nationality keeps Irish citizenship. Irish citizenship ends by renunciation: an adult citizen who is or is about to become a citizen of another country may lodge a declaration of alienage with the Minister, if ordinarily resident outside the State (section 21). Some other countries require renunciation of Irish citizenship as a condition of their own nationality. |
| Australia | Not required | None needed: the eligibility requirements for conferral in section 21 of the Citizenship Act include no condition about giving up another nationality. | No loss | Acquiring another nationality is not a ground on which Australian citizenship ends. Citizenship ends only by approved renunciation (the person must hold, or be about to acquire, another nationality), by ministerial revocation in the cases listed, or by a court cessation order. |
| Sweden | Not required | None needed: Swedish law does not require applicants to give up their previous nationality. Whether the previous nationality is kept depends on the law of the other country. | No loss | A Swedish citizen who becomes a citizen of another country can keep Swedish citizenship. Loss by operation of law applies to a person born abroad who has never lived in Sweden, at the age of 22, unless they apply to keep it. Release from Swedish citizenship is possible on application. |
| Austria | Required, with exceptions | The renunciation requirement does not apply to stateless persons, to cases under § 10 Abs. 6 (extraordinary achievements in the particular interest of the Republic, confirmed by the Federal Government), § 16 Abs. 2 or § 17 Abs. 4, or where leaving the previous nationality is not possible or not reasonable (§ 20 Abs. 3 Z 2), or would require a disproportionate payment (§ 20 Abs. 4). | Loss, unless retention approved | Austrian nationality is lost by anyone who acquires a foreign nationality on their own application, declaration or express consent, unless retention was approved before the acquisition (§ 27 Abs. 1). Retention must be approved where it is in the Republic's interest (with reciprocity, where it applies, and conditions of § 10 Abs. 1 Z 2-6 and 8), or in the child's best interest for minors (§ 28 Abs. 1); similar rules apply to persons who acquired nationality by descent (§ 28 Abs. 2). A person without full legal capacity loses it only with the legal representative's consent (§ 27 Abs. 2). |
| Switzerland | Not required | None stated. The Swiss authorities cannot say whether the applicant's previous country will treat naturalisation in Switzerland as a loss of that nationality; the applicant must ask that country's authorities. | No loss | Swiss citizens who acquire another nationality abroad do not have to give up Swiss citizenship, unless the other state requires renunciation of the previous nationality as a condition of acquiring its own. |
| Denmark | Not required | None needed: the rule making Danish nationality conditional on losing other nationalities was repealed with effect from 1 September 2015. | No loss (since 1 Sept 2015) | Since 1 September 2015, acquiring a foreign nationality no longer causes loss of Danish nationality. Loss through acquiring a foreign nationality applies only to those who did so before that date. |
| Norway | Not required | None needed: since 1 January 2020 a person may hold one or more nationalities in addition to Norwegian, and applicants do not have to tell the Norwegian authorities that they wish to keep their previous nationality. Whether the previous nationality is kept depends on the law of the other country. | No loss | A Norwegian citizen who becomes a citizen of another country on or after 1 January 2020 does not lose Norwegian citizenship. A separate rule applies at age 22: a person who became Norwegian at birth and holds another nationality loses Norwegian citizenship at 22 unless they have lived in Norway for two years, or in Nordic countries for seven years, before turning 22, or have applied to keep it. Those who hold only Norwegian citizenship at 22 are not affected. |
Before you rely on it
This comparison covers national rules. Regional or local rules can apply on top of them, and rules change. A rule marked “to verify” has not yet been confirmed against an official source. Each country page links to the official sources, and those are the place to confirm the details before you act.
General information, not legal advice. Rules change: check the official source before you fly or ride.