Do You Lose Your British Citizenship If You Become a Citizen of Another Country? Understanding the Implications and Rules

No. Becoming a citizen of another country does not automatically end your British citizenship. The UK permits dual and multiple citizenship, so you can normally remain British while acquiring another nationality.

The more important question is whether the other country allows dual nationality. Some countries require applicants to renounce an existing citizenship, while others may withdraw their nationality in certain circumstances. Check that country’s rules before applying. Our guide on how UK dual citizenship works explains the wider position.

The basic UK rule

The British Nationality Act 1981 does not make acquiring another nationality a reason for automatically losing British citizenship. You can hold more than two nationalities where the laws of all the countries concerned permit it.

Dual nationality can still affect travel and consular assistance. For example, British authorities may have limited ability to help while you are in the country of your other nationality.

How British citizenship can be lost

The main legal routes are voluntary renunciation and deprivation.

Scenario	Effect on British citizenship
You acquire another nationality	You normally remain British
You formally renounce British citizenship	Citizenship ends when the declaration is registered
Another country requires sole nationality	You may need to renounce British citizenship to qualify
A lawful deprivation order is made	Citizenship ends subject to the applicable legal process
You apply to resume citizenship	Registration may be by entitlement or discretion

Renunciation

Renunciation is a deliberate legal process. You must normally be aged 18 or over, have capacity and either already possess another nationality or expect to acquire one. Citizenship ends only when the Home Office registers the declaration.

If the declaration was registered because you expected to obtain another nationality, it will not take effect if you do not acquire that nationality within six months. The renunciation application fee is £513 as of July 2026.

Deprivation

The Home Secretary can deprive someone of British citizenship in defined circumstances, including where it was obtained through fraud, false representation or concealment of a material fact, or where deprivation is considered conducive to the public good. Simply acquiring a second passport is not a ground for deprivation. Our guide on whether the UK can strip your citizenship explains the rules and appeal rights.

The risk may come from the other country

Before applying overseas, confirm whether the new country:

• permits dual citizenship;

• requires formal renunciation of British citizenship;

• applies different rules to adults and children; or

• places restrictions on travel, public office, military service or property ownership.

The practical trade-offs are covered in our guide to the pros and cons of holding two nationalities.

Can you resume British citizenship after renouncing it?

You may have a one-time entitlement to resume British citizenship if you renounced it to retain or acquire another nationality and meet the statutory conditions. These include the relevant connection to the UK and the good-character requirement.

Where that entitlement does not apply, or has already been used, registration is discretionary. Applications are made using Form RS1 guidance. Citizenship takes effect from the date of registration and is not backdated. The current adult registration fee for an RS1 application is £1,670.

What to check before applying

Consider the tax implications of dual citizenship, although citizenship alone does not usually determine UK tax residence. Review the rules for travelling on two passports and the wider legal perks and pitfalls.

Nationality decisions may also affect future children, family arrangements and assets. Our family law solicitors, child custody solicitors and conveyancing solicitors can assist with related matters. A power of attorney may help where your affairs span more than one country.

Check the rules before you commit

The UK normally allows you to keep British citizenship when you acquire another nationality, but the other country’s law may change the outcome. Speak to Athi Law before renouncing, resuming or applying for another nationality so you understand the consequences.