Citizenship by Descent: Can You Claim It?

How Citizenship by Descent Works

British citizenship by descent is one of the ways a person can become British automatically at birth. It applies to children born outside the UK to a British parent.

The key distinction in British nationality law is between citizenship "otherwise than by descent" (OTD) and citizenship "by descent":

• Otherwise than by descent: People who were born in the UK to a British or settled parent, or who became British through naturalisation or registration. This is the "stronger" form of citizenship.
• By descent: People who acquired citizenship through a parent, typically because they were born abroad. This form of citizenship has limitations on what it can pass to the next generation.

If your parent was a British citizen "otherwise than by descent", you automatically became British at birth, even if you were born outside the UK. This makes you a British citizen "by descent".

The One-Generation Limit

The most important rule to understand is the one-generation limit. British citizenship by descent can only pass to one generation born outside the UK.

Here is how it works in practice:

• Generation 1 (born in UK): Sarah is born in London. She is British "otherwise than by descent".
• Generation 2 (born abroad): Sarah moves to Australia and has a son, James, born in Sydney. James is automatically British "by descent" because his mother is British OTD.
• Generation 3 (born abroad): James stays in Australia and has a daughter, Emma, also born in Sydney. Emma is not automatically British, because James is only British "by descent".

This rule exists to prevent citizenship from being passed indefinitely to people who may have no real connection to the UK. However, there are ways around it in certain circumstances.

Exceptions and Ways Around the One-Generation Limit

Crown Service

If the British citizen by descent parent was in Crown service (for example, working for the UK government, armed forces, or diplomatic service) at the time of the child's birth, the child may be British regardless of the one-generation limit.

Registration Under Section 3(2)

If a British citizen by descent lives in the UK with their child for 3 continuous years before the child turns 18, they can apply to register the child as British. The child must not have been absent from the UK for more than 270 days during those 3 years.

Registration Under Section 3(5)

Parents can apply to register a child born abroad as British if the Secretary of State considers it appropriate. This is a discretionary power and each case is considered on its merits.

Moving to the UK

If a child who is not automatically British moves to the UK and lives here, they may become eligible for citizenship through other routes (such as residence-based registration after 10 years, or naturalisation after gaining ILR).

Historical Rules and Corrections

Before 1983

The current rules on citizenship by descent came into effect on 1 January 1983 under the British Nationality Act 1981. Before that, British nationality law was different. People born before 1983 may have different entitlements depending on the laws in force at the time of their birth.

Gender Discrimination

Before 1983, British citizenship (then called "Citizen of the UK and Colonies") could only pass to children born abroad through the father. Mothers could not pass citizenship to children born outside the UK.

This was corrected by Section 4C of the British Nationality Act 1981, which allows people who would have been British if the law had applied equally to mothers and fathers to register as British citizens.

Unmarried Fathers

Before 1 July 2006, children of unmarried British fathers did not automatically acquire citizenship by descent. Only the mother's nationality was relevant for children born outside marriage.

Section 4G now allows people born before 1 July 2006 to an unmarried British father to register as British. See our MN1 form guide for more details.