32 destinations
Citizenship, compared.
How long naturalization takes, what it requires and whether you can keep the passport you hold today.
Europe
AustriaConferral of citizenship after ten years · Early conferral after six years10 years; 6 years in specific cases
Dual citizenship: Not allowedBulgariaNaturalization under the Bulgarian Citizenship ActVaries; confirm with the Ministry of Justice
Dual citizenship: RestrictedCyprusNaturalization by years of residence (form M127) · Naturalization for highly skilled employees (Article 111B(2))7 of 10 years plus 12 months; Greek at B1
Dual citizenship: AllowedDenmarkNaturalisation (indfødsret)9 years' residence plus permanent residence
Dual citizenship: AllowedEstoniaEstonian citizenship by naturalization8 years of residence, 5 of them permanent
Dual citizenship: Not allowedFinlandFinnish citizenship by application5 or 8 years of residence, depending on the case
Dual citizenship: AllowedFranceNaturalization by decree (naturalisation par décret)5 years; 2 years in specific cases
Dual citizenship: AllowedGermanyNaturalization (Einbürgerung, section 10 Nationality Act) · Naturalization after three years for special integration (repealed)5 years (3-year route repealed Oct 2025)
Dual citizenship: AllowedIrelandNaturalisation as an Irish citizen5 years' reckonable residence; 8-year bill proposed
Dual citizenship: AllowedItalyCitizenship by residence (Article 9, Law 91/1992)10 years of legal residence
Dual citizenship: AllowedLatviaNaturalization5 years after obtaining permanent status
Dual citizenship: RestrictedLithuaniaCitizenship by naturalization10 years of residence, holding permanent residence
Dual citizenship: Not allowedMaltaNaturalization (Maltese Citizenship Act, Article 10(1)) · Citizenship by merit (Article 10(9)) · Former citizenship by investment (exceptional services by direct investment)5 years within 7, including the final 12 months
Dual citizenship: AllowedNetherlandsNaturalisation5 years (10-year bill proposed in 2025)
Dual citizenship: RestrictedPortugalNaturalization (Nationality Law 37/81, as amended in 2026)10 years; 7 for CPLP and EU nationals
Dual citizenship: AllowedSpainNationality by residence10 years; 2 for Ibero-American nationals
Dual citizenship: RestrictedUnited KingdomNaturalisation as a British citizen5 years' residence incl. 12 months with ILR
Dual citizenship: Allowed
Dual citizenship: Not allowedBulgariaNaturalization under the Bulgarian Citizenship ActVaries; confirm with the Ministry of Justice
Dual citizenship: RestrictedCyprusNaturalization by years of residence (form M127) · Naturalization for highly skilled employees (Article 111B(2))7 of 10 years plus 12 months; Greek at B1
Dual citizenship: AllowedDenmarkNaturalisation (indfødsret)9 years' residence plus permanent residence
Dual citizenship: AllowedEstoniaEstonian citizenship by naturalization8 years of residence, 5 of them permanent
Dual citizenship: Not allowedFinlandFinnish citizenship by application5 or 8 years of residence, depending on the case
Dual citizenship: AllowedFranceNaturalization by decree (naturalisation par décret)5 years; 2 years in specific cases
Dual citizenship: AllowedGermanyNaturalization (Einbürgerung, section 10 Nationality Act) · Naturalization after three years for special integration (repealed)5 years (3-year route repealed Oct 2025)
Dual citizenship: AllowedIrelandNaturalisation as an Irish citizen5 years' reckonable residence; 8-year bill proposed
Dual citizenship: AllowedItalyCitizenship by residence (Article 9, Law 91/1992)10 years of legal residence
Dual citizenship: AllowedLatviaNaturalization5 years after obtaining permanent status
Dual citizenship: RestrictedLithuaniaCitizenship by naturalization10 years of residence, holding permanent residence
Dual citizenship: Not allowedMaltaNaturalization (Maltese Citizenship Act, Article 10(1)) · Citizenship by merit (Article 10(9)) · Former citizenship by investment (exceptional services by direct investment)5 years within 7, including the final 12 months
Dual citizenship: AllowedNetherlandsNaturalisation5 years (10-year bill proposed in 2025)
Dual citizenship: RestrictedPortugalNaturalization (Nationality Law 37/81, as amended in 2026)10 years; 7 for CPLP and EU nationals
Dual citizenship: AllowedSpainNationality by residence10 years; 2 for Ibero-American nationals
Dual citizenship: RestrictedUnited KingdomNaturalisation as a British citizen5 years' residence incl. 12 months with ILR
Dual citizenship: Allowed
Americas
BrazilOrdinary naturalization (naturalização ordinária) · Extraordinary naturalization (naturalização extraordinária)4 years of residence, plus Portuguese
Dual citizenship: AllowedCanadaGrant of Canadian citizenship (adults)1,095 days in Canada within 5 years
Dual citizenship: AllowedChileCarta de nacionalización5 years from the temporary permit's stamping
Dual citizenship: AllowedUnited StatesNaturalization (Form N-400)5 years as a permanent resident
Dual citizenship: Allowed
Dual citizenship: AllowedCanadaGrant of Canadian citizenship (adults)1,095 days in Canada within 5 years
Dual citizenship: AllowedChileCarta de nacionalización5 years from the temporary permit's stamping
Dual citizenship: AllowedUnited StatesNaturalization (Form N-400)5 years as a permanent resident
Dual citizenship: Allowed
Asia-Pacific
AustraliaAustralian citizenship by conferral4 years' residence incl. 12 months as PR
Dual citizenship: AllowedHong KongNaturalisation as a Chinese NationalDiscretionary naturalization as a Chinese national
Dual citizenship: Not allowedJapanNaturalization (Nationality Act, Article 5)5 years by law; 10 in principle since April 2026
Dual citizenship: Not allowedMalaysiaCitizenship by naturalization (Article 19 of the Federal Constitution)10 of the last 12 years' residence
Dual citizenship: Not allowedNew ZealandCitizenship by grant5 years as a resident, 240 days a year
Dual citizenship: AllowedSingaporeSingapore Citizenship (application by permanent residents)2 years as a PR, aged 21 or over
Dual citizenship: Not allowedSouth KoreaGeneral naturalization (Nationality Act, Article 5)5 years' residence while holding F-5 status
Dual citizenship: RestrictedTaiwanNaturalization under the Nationality Act · Naturalization for high-level professionals5 consecutive years, over 183 days each
Dual citizenship: RestrictedThailandNaturalization under the Nationality Act, B.E. 2508 (1965)5 consecutive years' domicile; Thai required
Dual citizenship: Restricted
Dual citizenship: AllowedHong KongNaturalisation as a Chinese NationalDiscretionary naturalization as a Chinese national
Dual citizenship: Not allowedJapanNaturalization (Nationality Act, Article 5)5 years by law; 10 in principle since April 2026
Dual citizenship: Not allowedMalaysiaCitizenship by naturalization (Article 19 of the Federal Constitution)10 of the last 12 years' residence
Dual citizenship: Not allowedNew ZealandCitizenship by grant5 years as a resident, 240 days a year
Dual citizenship: AllowedSingaporeSingapore Citizenship (application by permanent residents)2 years as a PR, aged 21 or over
Dual citizenship: Not allowedSouth KoreaGeneral naturalization (Nationality Act, Article 5)5 years' residence while holding F-5 status
Dual citizenship: RestrictedTaiwanNaturalization under the Nationality Act · Naturalization for high-level professionals5 consecutive years, over 183 days each
Dual citizenship: RestrictedThailandNaturalization under the Nationality Act, B.E. 2508 (1965)5 consecutive years' domicile; Thai required
Dual citizenship: Restricted
Middle East
In short.
Naturalization and dual citizenship
Naturalization is the usual route to citizenship for founders. It typically follows permanent residence and requires several years of lawful residence, language skills, knowledge of the country and good character. The total time from first permit to passport ranges from a few years to more than a decade, so it is worth comparing early if a second citizenship is your goal.
Dual citizenship rules decide whether you can keep your current nationality. Some countries allow it without conditions, some only for certain nationalities or cases, and some require you to renounce your previous citizenship. Where a destination offers citizenship by investment, its country page sets out the current status of that program.
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