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 (sometimes shortened to OTD): 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)

This is an entitlement that looks at the parent's past residence rather than the child's. It applies where the parent was a British citizen by descent at the time of the birth, that parent's own parent was a British citizen otherwise than by descent, and the parent lived in the UK or a qualifying territory for a 3-year period ending before the birth, being present at the start of it and absent for no more than 270 days across it.

Registration Under Section 3(5)

This is the route for a family that has moved to the UK. The child and both parents must have been in the UK or a qualifying territory for the 3 years before the application, each present at the start of that period and each absent for no more than 270 days across it, and both parents must consent. The child must still be a minor when the application is made.

Registration Under Section 3(1)

Section 3(1) is a general discretion: while a person is a minor, the Secretary of State may register them as a British citizen. It is discretionary, and each case is considered on its own facts.

Growing Up in the UK

A child who is not automatically British but grows up here may reach citizenship another way, for example through indefinite leave to remain (settlement) and then naturalisation as an adult. Registering a child as a British citizen costs £1,000; registering an adult costs £1,540; and there is a £130 citizenship ceremony fee where a ceremony applies.

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 lets someone born before 1 January 1983 register as a British citizen where they would have become one had the law treated mothers and fathers equally. GOV.UK sets no application fee for this route: the page says "You'll need to pay £130 to attend a citizenship ceremony", and lists no application fee alongside it. Do not assume the £1,709 naturalisation fee applies to a registration route.

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.

Proving Citizenship by Descent

If you believe you are British by descent, you do not need to apply for citizenship. You already have it (assuming the conditions were met at your birth). However, you need to prove your citizenship to obtain a British passport.

To apply for your first British passport, you need to provide:

• Your birth certificate
• Your parent's birth certificate (or naturalisation certificate)
• Your parents' marriage certificate (if applicable)
• Your parent's British passport (if available)

HM Passport Office checks the claim to citizenship before issuing a passport, so a first application takes longer than a renewal and asks for more. An adult passport costs £102 applying online, and HM Passport Office asks applicants to allow up to 10 weeks. Fees for nationality applications are separate: see our guide to UK visa and citizenship fees.

Citizenship by Descent and Dual Nationality

Being British by descent does not prevent you from holding another nationality. The UK allows dual citizenship, so you can be British and a citizen of the country where you were born.

However, the country where you were born may have its own rules about dual nationality. Check the laws of that country to understand whether holding British citizenship affects your other nationality.

Common Scenarios

Born abroad to a British parent who was born in the UK

You are British by descent from birth. A British passport application is how that is put on the record. See our citizenship travel benefits guide for what your passport unlocks.

Born abroad to a British parent who was naturalised in the UK

You are automatically British by descent. Your parent's naturalisation counts as citizenship "otherwise than by descent".

Born abroad to a parent who was themselves born abroad to a British parent

The one-generation limit applies: a parent who is British "by descent" does not pass citizenship to a child born outside the UK. The registration routes under sections 3(1), 3(2) and 3(5) above are where this case usually goes, and Crown service is the other exception.

Born abroad before 1983 to a British mother

Under the law as it then stood, citizenship passed to a child born abroad through the father only. Section 4C now allows registration in that case, with no application fee and a £130 ceremony fee. See our citizenship through grandparents guide for related routes.

Born abroad to an unmarried British father before July 2006

Under the law as it then stood, an unmarried British father did not pass citizenship to a child born abroad. Section 4G now allows registration in that case. For the good character requirement that applies to registration, see our separate guide.

Getting Advice

Citizenship by descent cases can be straightforward or very complex, depending on when you were born, where your parents were born, and what laws were in force at the time. If you are unsure of your status, consider:

• Checking the GOV.UK citizenship checker
• Reading our guide to applying alone or with a solicitor
• Speaking to a solicitor, or an adviser registered with the Immigration Advice Authority, which took over from the Office of the Immigration Services Commissioner on 16 January 2025. Nationality advice about an individual case is regulated in the UK
• Contacting HM Passport Office, which decides whether a passport can be issued on the documents you hold

Questions and answers