UK Dual Citizenship: 2026 Guide for US Nationals

Dual citizenship (also called dual nationality) is a situation where an individual simultaneously holds the nationality of two separate countries. In this case, a British nationality and an American citizenship.

You can acquire a second citizenship through various pathways, such as by birth, descent, naturalisation, marriage, military service, or investment. However, this is only possible if both countries allow dual nationality.

Most countries allow dual citizenship, some allow dual citizenship for specific categories of people (e.g., those born with dual nationality), while others completely restrict dual citizenship. The top countries that allow dual nationality include the UK, the USA, Australia, Canada, France, and Germany.

While the top countries that restrict dual citizenship include Austria, India, Japan, China, Saudi Arabia, and Singapore.

If you’re from a country that prohibits dual citizenship, you may be required to renounce your original citizenship upon acquiring British citizenship through naturalization.

Page Contents

• Dual Citizenship Overview
• Does the UK Allow Dual Citizenship?
• Who is Eligible for UK Dual Citizenship?
• Requirements for UK Dual Citizenship
• Required Documents for British Dual Citizenship
• Applying for UK Dual Citizenship
• Attending a British Citizenship Ceremony
• Application Cost for Citizenship Application
• Benefits of UK Dual Citizenship
• Disadvantages of Dual Citizenship in the UK
• Travel Guidelines for Dual Citizens
• Traveling to and from the UK
• How to Apply for a British Passport
• UK Dual Citizenship Passport Rules Explained
• Applying for a Certificate of Entitlement
• How Can Total Law Help?
• Frequently Asked Questions

The UK and the US both allow dual citizenship. This means Americans can become British citizens provided they qualify through any of the available pathways. UK nationals can also become American citizens if eligible. You will not have to renounce your American or British citizenship to acquire the other.

There’s no specific application for UK-US dual citizenship. You can apply to obtain British citizenship through any of the qualifying routes while maintaining your US citizenship. There are many routes to acquiring British citizenship. The most common routes include:

• British citizenship by birth
• British citizenship by descent
• British citizenship by marriage
• British citizenship by naturalization

Similarly, UK nationals do not have to make a special application for dual citizenship in the US. You can simply apply for American citizenship if you meet the eligibility requirements while maintaining your British citizenship.

The eligibility criteria for dual British citizenship vary depending on your pathway to acquiring British citizenship. Foreign nationals, including US citizens, who do not qualify for UK citizenship by birth or descent can acquire dual UK nationality through naturalization.

You may be eligible to apply for British citizenship by naturalization if:

• You’re 18 years or older
• You have held indefinite leave to remain or settled status in the UK for at least 12 months, except if you’re the spouse/partner of a British or Irish citizen
• You must have lived in the UK for at least 5 years (or 3 years if you’re married to a UK national)
• Have not violated UK laws or immigration rules
• You are proficient in the English language, Welsh, or Scottish Gaelic
• You have passed the Life in the UK test

Obtaining UK dual nationality through naturalization is primarily based on long-term legal residence in the UK under eligible visas/permits. You must meet the following requirements to qualify for dual British citizenship.

You must:

• You must have legally resided in the UK for at least 5 years on the date you submit your citizenship application. If you’re the spouse/civil partner of a British or Irish citizen, you must have lived in the UK for at least 3 years before your application
• Have had ILR, settled status under the EU Settlement Scheme, or indefinite leave to enter the UK for at least 12 months (12-month timeframe does not apply if you have a British citizen spouse/partner)
• Not have spent more than 450 days outside the UK in the 5 years preceding your application
• Not have spent more than 90 days outside the UK in the 12 months before your naturalisation requirement
• Demonstrate that you intend to continue to live in the UK
• Pass the British citizenship test. The test examines your knowledge of British history, culture, and values
• Meet the good character requirement and have a clean criminal record

Note that time spent in the UK outside of immigration control does not count as qualifying residence for a UK citizenship application. This includes stays in the UK as a diplomat, a member of a diplomat’s household or staff, or a member of visiting foreign armed forces.

When applying for dual British citizenship, you must submit relevant documents that prove your eligibility for British nationality. The specific required documents vary based on your circumstances and your citizenship application route.

For example, the required documents for British citizenship through naturalization generally include:

• A completed British citizenship application form
• Your valid US passport or other valid proof of identity
• Biometric Residence Permit (if you have one)
• Proof of circumstance, such as a marriage certificate or civil partnership registration, if you’re applying as the spouse/partner of a UK citizen. You may also be required to provide your spouse/partner’s British passport
• Proof of continuous residence in the UK for the last 5 years
• Proof that you were present in the UK at least 5 years before your citizenship application
• Evidence of your Indefinite Leave to Remain status or other settled status
• Life in the UK Test pass certificate
• Proof of at least B1 level proficiency in the English language
• Evidence that you meet the good character requirement
• Details of any absences from the UK during the qualifying period
• Proof of payment of the UK citizenship application fee

You should gather all required documents before starting your citizenship application. Depending on your situation, you may be required to provide additional documentation if necessary.

There is no specific application process for dual nationality in the UK. You only need to apply for British nationality (for the naturalization or marriage route) or register your British nationality (in case of birth or descent).

If your registration/application is successful, you’ll be granted British citizenship in addition to your American citizenship. You’ll automatically become a US-UK dual nationality holder.

UK citizenship applications can be made online on the UK Visas and Immigration (UKVI) services website or by post, regardless of your eligibility pathway. You can make the application yourself or use an authorized agent or legal representative.

If you want to naturalize as a British citizen, you can apply for dual British citizenship after 12 months of holding an ILR or other UK settled status. Spouses or partners of UK citizens can apply to naturalise as British citizens immediately after obtaining indefinite leave to remain.

Once you’ve determined that you’re eligible for British citizenship and have prepared all supporting documents, you can apply by completing the naturalisation form on the UKVI website.

After submitting the online form, you’ll be required to schedule an appointment with the UK Visa and Citizenship Application Service (UKVCAS) to submit your biometric information (your photo and fingerprints).

You can upload your documents on the service portal when you submit your application, or you could bring them to your UKVCAS appointment. The Home Office will evaluate your application and will usually grant a decision within 6 months.

If your naturalization application is successful, the UKVI will notify you and send you a citizenship ceremony invitation. You must schedule and attend a citizenship ceremony within three months of receiving the invitation. If you do not book and attend your ceremony within the 90-day timeframe without a valid reason, your application for citizenship will be refused.

Citizenship ceremonies are organized by local authorities and are usually done in groups. You must bring your invitation to the ceremony as proof of citizenship approval. You can also bring two guests.

During the ceremony, you’ll have to make an Oath of Allegiance and a pledge to the UK. This means you’re agreeing to respect the laws, rights, and freedoms of the UK.

You’ll be presented with your British citizenship certificate and a welcome pack at the end of the ceremony. You must return your BRP (if you have one) to the Home Office within 5 working days of receiving your British naturalisation certificate. Failure to do so can attract a £1,000 fine.

Note that a British citizenship certificate cannot be used as a travel document. You can apply for a British passport or a certificate of entitlement once you receive your British certificate of citizenship.

Application for British citizenship through naturalization costs £1,839 for adult applicants. This also includes the citizenship ceremony fee of £130.

Adults (over 18s) must attend a Citizenship ceremony when they register as a British citizen. The biometric appointment with UKVCAS is free. Aside from the citizenship application fee, you may incur other expenses in preparing your supporting documents.

To register their British nationality by birth or descent, adult applicants will have to pay a fee of £1,540. The registration fee is £1,000 for child applicants.

Holding a US-UK dual nationality in the UK comes with a lot of benefits. With two of the world’s strongest passports, you’ll enjoy enhanced global mobility and all the benefits available to citizens in both countries.

Some of the benefits of UK-US dual citizenship include:

• Right to live, work, and study in both the UK and the US
• Travel between both countries without time or immigration restrictions
• Access to public funds and all social welfare benefits you’re eligible for
• Right to vote in elections and stand for public offices
• Right to hold a British and an American passport
• Right to use the National Health System (NHS) and all other public social infrastructure in the UK. You will no longer have to pay an immigration health surcharge to use the NHS

Although dual citizenship has numerous benefits, it also has some disadvantages.

You must abide by the laws of both nations to maintain your citizenship, regardless of your country of residence, including taxes. This can sometimes result in your paying higher taxes or double taxation.

As a dual citizen, you cannot access diplomatic assistance from the UK government when you’re in your other country. For example, you cannot get diplomatic help from the UK embassy when visiting the US as an American-British citizen.

Dual citizenship can also cause a conflict of interest if both countries have a major disagreement or go to war, as you can only perform military service in one country. You will have to pick a side and may lose the other citizenship in the process.

UK dual nationals cannot use their British naturalisation certificate as a travel document. You must obtain a UK passport or a certificate of entitlement if you do not want a British passport. The certificate of entitlement will be attached to your foreign passport.

You can still travel outside the UK using your US passport, but you may not be allowed to board a carrier to enter the UK without a valid British passport, an Irish passport, or a certificate of entitlement.

You may be allowed to board a carrier to enter the UK if you have an expired British passport issued in 1989 or later and a passport from a country eligible for UK electronic travel authorization (ETA). Your personal details on both passports must match.

You can travel to the UK as a dual national using a:

• Valid UK passport
• Valid Irish passport
• Certificate of entitlement

Dual British citizens can no longer enter the UK with just their foreign passports, except for Irish nationals. British dual citizens cannot apply for an ETA with their foreign passports.

Carriers have to verify your identity and immigration status before allowing you to board a flight, ferry, or vessel headed for the UK, and a British passport is the only approved means of doing so for dual British nationals.

In some cases, carriers may allow you to board if you have an expired UK passport. However, this is at the carrier’s discretion and is not always guaranteed.

You can apply for a British passport as a dual national. If you have a foreign passport (such as your American passport), the name on your other passport application must match the name on your British passport application. If it does not, you should change the name on your other passport before applying for a British passport.

After completing the online application, you must send your certificate of British naturalisation and your foreign passport to the HM Passport Office. The documents will be returned to you once your passport application is successful.

The standard online UK passport application fee for an adult is £102 and £66.50 for a child passport. Paper applications cost £115.50 for adults and £80 for children under 16 years.

British passport applications are usually processed within 2-3 weeks. A standard UK passport is valid for 10 years. If you do not want a British passport, you can apply for a certificate of entitlement instead.