Dual citizenship (also known as dual nationality) is allowed in the UK. This means you can be a British citizen and also a citizen of other countries.
Many countries don’t accept dual nationality – check the law in the other country before you apply.
You can’t have dual citizenship if you’re a British subject or a British protected person unless you’re a British subject from the Republic of Ireland.
To get dual citizenship in the UK, apply for citizenship in the normal way.
As a dual national you can’t get diplomatic help from the British government when you are in the other country where you hold citizenship.
For example, if you hold both British and Chinese citizenship you can’t get diplomatic help from the UK when you’re in China.
Dual citizenship, marriage and children
You don’t automatically become a British citizen when you marry a person from the UK. You need to apply as the spouse of a British citizen.
In some countries, a married person is automatically counted as having their partner’s nationality. Children may also automatically have a parent’s nationality even if they were born abroad.
Check with the country’s consulate or high commission in the UK to find out about that country’s laws on dual nationality.