Dual Citizenship Rules Compared: US, Canada, UK and Australia

The United States, Canada, the United Kingdom and Australia all allow dual citizenship. None of them makes you give up your original nationality when you naturalise. The real question is whether your home country lets you keep its citizenship. India and China, for example, do not, so their citizens lose their original nationality when they voluntarily take another one.

Key points

• All four countries let you hold another citizenship alongside theirs.
• Your country of origin decides whether you keep your first citizenship. India and China do not allow dual nationality; the Philippines lets natural-born Filipinos retain or reacquire citizenship.
• Time to citizenship ranges from 3 years of physical presence (Canada) to about 6 years in total (UK, via ILR).
• Dual citizens usually must use the passport of the country they are entering. The US and Canada say this directly.
• As of October 2026, none of the four has announced plans to restrict dual citizenship, but the UK has proposed changes to settlement that would delay citizenship for many.

Dual citizenship rules at a glance

	United States	Canada	United Kingdom	Australia
Allows dual citizenship?	Yes, by practice: US law does not require you to choose one nationality	Yes	Yes	Yes (Australians since 4 April 2002)
Must you renounce your old nationality?	The oath includes renouncing foreign allegiance, but the US does not require proof you lost the other nationality	No	No	No
Passport rule	Must enter and leave the US on a US passport	Need a Canadian passport to return to Canada by air	No British consular help in the other country of citizenship	Smartraveller advises using your Australian passport to enter and leave Australia
Official source	State Department	Travel.gc.ca	GOV.UK	Smartraveller

United States

The State Department says US law does not require a US citizen to choose between US citizenship and another nationality. You must enter and leave the United States on your US passport, and a US citizen cannot get a US visa. Your other country may require you to use its passport to enter there, which does not put your US nationality at risk.

New citizens recite an oath that includes renouncing allegiance to other states. In practice, the US does not ask you to prove you gave up your old citizenship; what happens to it depends on your home country’s law.

Canada

Canada “allows you to have multiple citizenships while keeping your Canadian citizenship”, according to the Government of Canada travel site. The practical rule to remember: you need a valid Canadian passport to return to Canada by air, even if you are only transiting. Some countries do not recognise dual citizenship, and Canada may be limited in the help it can give you there.

United Kingdom

GOV.UK says dual citizenship “is allowed in the UK”. You do not need to apply for it. The main limitation: if you are in the other country where you are a citizen, the UK cannot usually give you diplomatic help.

Australia

Australia does not require new citizens to give up their previous nationality. Australian citizens who took another citizenship before 4 April 2002 generally lost Australian citizenship under the old section 17 of the Australian Citizenship Act 1948; that rule was repealed in 2002 and was not retrospective. People affected may be able to apply to resume Australian citizenship. When travelling, Smartraveller advises using your Australian passport to enter and leave Australia, and warns that if you use your other passport in that country, Australia’s ability to help you may be limited.

How long it takes to become a citizen

	United States	Canada	United Kingdom	Australia
Main residence rule	5 years as a green card holder; 30 months physically present	1,095 days physically present in the 5 years before applying	5 years’ residence, max 450 days outside the UK, max 90 days in the last year	4 years living in Australia on a valid visa
Time as permanent resident	Full 5 years (3 if married to and living with a US citizen)	Time before PR counts as half days, up to 365 days	ILR (or settled status) for 12 months, in most cases	At least the last 12 months as a permanent resident
Absence limits	Trips over 6 months may break continuous residence	Built into the 1,095-day count	450 days in 5 years; 90 in the last 12 months	Max 12 months away in 4 years, and 90 days in the last 12 months
Test	English and civics (20 questions asked, 12 to pass)	Citizenship test for ages 18–54	Life in the UK test and English (B1)	Citizenship test for most people aged 18–59
Fee (Oct 2026)	$760 paper / $710 online	CAD 653 (adult)	£1,709 + £130 ceremony	AUD 595 (general conferral)

Sources: USCIS, IRCC, GOV.UK, Home Affairs, Home Affairs Form 1298i fees.

For the full process in each country, see our guides to applying for US citizenship, Canadian citizenship requirements, British naturalisation and Australian citizenship.

UK caution: the government consulted on “earned settlement”, which would move the baseline for ILR to 10 years for many routes, and has floated “earned citizenship”. As of October 2026, neither is law, and the 5-year ILR route still applies.

Will you lose your original citizenship? Common source countries

This is where most people get caught out. Check before you apply, because the loss can be automatic.

India: no dual citizenship

India does not allow its citizens to hold another nationality. According to the Embassy of India in Helsinki, under Section 9 of the Citizenship Act 1955, a person who voluntarily obtains another country’s nationality or passport “ceases to be an Indian national” and must surrender their Indian passport.

What this means in practice:

• Once you naturalise in the US, Canada, the UK or Australia, you are no longer an Indian citizen.
• You must surrender your Indian passport through the Indian mission, and fees apply. Do this before applying for an Indian visa or OCI.
• Many former Indian citizens apply for an Overseas Citizenship of India (OCI) card. OCI is a lifelong visa-like status. It does not give voting rights or the right to hold certain public offices, and it is not citizenship.

China: no dual nationality, automatic loss

China’s Nationality Law states in Article 3: “The People’s Republic of China does not recognize dual nationality for any Chinese national.” Under Article 9, a Chinese national who has settled abroad and is naturalised as a foreign national, or who voluntarily acquires a foreign nationality, automatically loses Chinese nationality. People in this position often need to deal with their hukou registration and Chinese passport, and enter China on a visa with their new passport. Check with the Chinese embassy or consulate where you live.

Philippines: retention and reacquisition allowed

Under Republic Act 9225 (the Citizenship Retention and Re-acquisition Act of 2003), natural-born Filipinos who become citizens of another country can retain or reacquire Philippine citizenship by taking an oath of allegiance before a Philippine consular officer or in the Philippines. Unmarried children under 18 can be included. Running for elected office in the Philippines has extra conditions.

Other countries

Rules vary widely. Some countries allow dual citizenship freely, some only with certain countries or with permission, and some remove citizenship automatically. Before you naturalise, check your home country’s nationality law with its embassy or consulate, and ask specifically about:

• automatic loss on naturalisation abroad
• any declaration or permission needed to keep citizenship
• passport surrender and fees
• effects on children born abroad
• property, inheritance or land-ownership rights that depend on citizenship
• military service obligations

Practical issues for dual citizens

1. Taxes. Citizenship and tax residence are different. The US taxes its citizens on worldwide income wherever they live, so US dual citizens abroad usually still have to file US returns. The other three generally tax by residence.
2. Travel documents. Keep both passports valid. Use the right one at each border, and make sure airline bookings match the passport you show.
3. Consular help. The UK and Canada both warn that their help may be limited in your other country of nationality.
4. Government jobs and security clearance. Some roles restrict or review dual citizens.
5. Passing citizenship to children. Each country has its own rules for children born abroad. Canada changed its citizenship-by-descent rules on 15 December 2025 under Bill C-3; see our Bill C-3 explainer.

What to do next

1. Confirm your home country’s rules before you lodge a citizenship application, especially if you are from India, China or another country that does not allow dual nationality.
2. Work out your eligibility date using the residence rules in the table above.
3. Plan any passport surrender, OCI or visa steps so you are not stuck unable to travel.
4. Read the country hubs: US, Canada, UK and Australia. Check /updates/ for changes such as the UK settlement reforms.
5. If you have property, inheritance or business interests in your home country, get advice there as well as from an immigration lawyer, RCIC, IAA-regulated adviser or registered migration agent.

This article is general information, not legal advice. Rules are as of October 2026.