British Citizenship Routes Explained 2025

British Citizenship Routes Explained 2025

Amira is 23 years old. She moved to the UK from Kenya when she was a child. She’s now exploring the main British citizenship routes 2025 to find out whether she qualifies through her parents, registration, or naturalisation. She moved to the UK from Kenya when she was a child. She has now finished university and recently received indefinite leave to remain. Amira feels ready to take the next step and apply for British citizenship. However, she is unsure if she qualifies through her parents, by registration, or by naturalisation.

In this article, you will learn the main ways a person can become a British citizen in 2025. It will help you understand whether you qualify by birth or descent, through registration, or by naturalisation.

British Citizenship Routes Explained 2025: The Three Main Routes to British Citizenship

There are three main ways to become a British citizen in 2025: by birth or descent, by registration or by naturalisation. 

Each route has its own rules, and which one applies will depend on your circumstances.

Citizenship by Birth or Descent

Many people believe that being born in the UK automatically makes someone a British citizen. This is not always the case. Whether a person is a citizen at birth depends on the situation of their parents at that time. You’ll always need to check this.

If someone is born outside the UK, they may still be a British citizen if one of their parents is British. In these cases, people can usually apply after turning 18, and successful applicants become British citizens, most often by descent However, this status works differently from citizenship by birth and does not always pass automatically to future generations.

Citizenship by Registration

Another way of becoming a British citizen is through registration. The rules in this area cover many different situations. Registration is often relevant for children under the age of 18. However, in some cases, adults can also register. This route is also for people who are connected to the UK but who do not automatically qualify by birth or descent.

Citizenship by Naturalisation

Naturalisation is the most common route for adults who move to the UK and make it their home. To apply, a person usually needs to hold indefinite leave to remain or settled status under the EU Settlement Scheme. They will also need to meet residence requirements to qualify. Naturalisation is the process that allows long-term residents to become full British citizens with all the rights that brings.

British Citizenship by Birth: Key Historical Rules

When looking at British citizenship by birth, the rules have changed over time. Two important dates are 1 January 1983 and 1 July 2006.

If Born in the UK Before 1 January 1983

If someone was born in the UK before 1 January 1983, they automatically became a British citizen. This was because the old nationality law (before the British Nationality Act 1981 came into force). It gave citizenship to most people born in the UK, regardless of their parents’ status.

If Born in the UK from 1 January 1983

From 1 January 1983 onwards, the rules became stricter. A child born in the UK would only be a British citizen at birth if at least one parent was a British citizen. The same rule applies for settled parents in the UK at the time of the birth. This meant that being born in the UK was no longer enough by itself to gain British citizenship.

If Born in the UK from 1 July 2006

Until 30 June 2006, only married fathers could pass on British citizenship to their children. This rule made it difficult for children born outside marriage to acquire citizenship. On 1 July 2006, the law changed and removed this requirement. Since then, fathers can pass on citizenship even if they were not married to the mother at the time of the birth.

British Citizenship by Descent

British citizenship by descent applies when a child is born outside the UK but has a parent who is a British citizen. The rules are similar to those for citizenship by birth, but with some important differences.

If Born outside the UK before 1 January 1983

For children born abroad before 1 January 1983, only the father could pass on citizenship if he was a citizen of the United Kingdom and Colonies (CUKC). This father also needed to be married to the child’s mother. Mothers could not normally pass on their citizenship until the law changed later.

If Born outside the UK After 1 January 1983

From this date, the British Nationality Act 1981 introduced the concept of British citizenship by descent. A child born outside the UK to a parent who is a British citizen “otherwise than by descent” usually becomes a British citizen automatically.

This means that if a parent is a British citizen through birth, registration, or naturalisation, they can normally pass citizenship on to their child born abroad.

Important Limitations

• Parents who are only settled in the UK (for example, holding indefinite leave to remain or settled status) but are not British citizens cannot pass on British citizenship by descent to a child born outside the UK. Such a child does not automatically become a British citizen.

• Parents who already hold British citizenship by descent also cannot usually pass it on to their child born abroad. This rule, known as the “one generation rule,” means that grandchildren born outside the UK normally do not automatically receive British citizenship.

British Citizenship by Registration

Registration is another way to acquire British citizenship. It is often used by children under 18, but in some cases adults can also apply. Unlike citizenship by birth or descent, registration is never automatic — it always requires an application and evidence.

Registration for Children Under 18

Children are the largest group of people who register as British citizens. Common situations include:

• when a child is born in the UK to parents who later became settled or British (for example, where the parents obtained indefinite leave to remain or citizenship after the child’s birth).
• Born in the UK and lived here for the first 10 years of life, even if the parents were not settled during that time.
• Born abroad to British parents by descent, where further connection to the UK is needed (for example, if the family moves back to the UK for three years).

In these cases, children usually apply while under 18, and if successful, they become British citizens otherwise than by descent — meaning they can normally pass citizenship on to their own children born abroad.

Discretionary Registration

The Home Secretary has wide powers to register any child under 18 if they think it is right to do so.

This is used in cases such as:

• Children whose parents are applying for naturalisation and want to include them in the application.
• Children who have lived in the UK for many years and have formed strong ties, even if their parents are not British.
• Situations where it is clearly in the best interests of the child, even if the strict legal requirements are not met.

This route is only for minors and cannot be used once a person turns 18.

Registration by Descent

There is a provision in the British Nationality Act 1981 that allow a child born abroad to be registered if one parent is British by descent and the family, has close connections to the UK — often shown through residence in the UK before the child’s birth. However, in certain circumstances, registration is also possible when the family (both parents and the child) to live in the UK for at least three years before applying.

These routes help preserve citizenship rights for families with British heritage but living overseas. They are normally available only to children under 18.

Registration of Stateless Children

A child who is born stateless (without any nationality) may have a right to be registered as a British citizen. The exact rules depend on when and where the child was born, but in general, if they live in the UK for a number of years without any nationality, registration may be possible.

This route reflects the UK’s international obligations to reduce statelessness and is usually open to children under 18, although in limited circumstances adults may also benefit.

Registration for Adults – Historical Unfairness

While most registration routes apply to children, there are important exceptions for adults. The law has been amended several times to correct past discrimination in nationality law. Adults can now register in cases where, historically, they were unfairly excluded.

Examples include:

• People born before 1983 to British mothers (who at that time could not always pass on citizenship).
• People born to unmarried British fathers before July 2006, who could not acquire citizenship through their father.
• Certain groups affected by historical errors, omissions, or discrimination in nationality law.

In these cases, applications can usually be made after the age of 18, and successful applicants will become British citizens (most often by descent).

British Citizenship by Naturalisation

Naturalisation is the most common route for adults who want to become British citizens. It is open to people who already hold indefinite leave to remain (ILR) or settled status. The requirements differ depending on whether you are married to or in a civil partnership with a British citizen.

Naturalisation if not married to a British citizen – Section 6(1)

If you are not the spouse or civil partner of a British citizen, you must meet a wider set of requirements. These include 9 key rules:

1. Good character – You must show that you have respected UK law and immigration rules.
2. English language requirement – You must pass an approved English test (or hold an exempt qualification).
3. Life in the UK Test – You must pass the Life in the UK Test.
4. Residence – You must have lawfully lived in the UK for at least 5 years before the date of your application.
5. Presence in the UK – You must have been physically present in the UK exactly 5 years before the date of your application.
6. Free from restrictions – You must have had ILR/settled status for at least 12 months before applying.
7. Absences – You must not have spent more than 450 days outside the UK in the last 5 years
8. Absences – and no more than 90 days outside the UK in the last 12 months.
9. Intention to Settle – you need to prove that you have intention to settle in the UK after you get your British citizenship

Naturalisation if married to a British citizen – Section 6(2)

If you are the spouse or civil partner of a British citizen, you may apply for naturalisation after only 3 years of lawful residence in the UK, instead of 5. However, you must still meet the following 8 key rules:

1. Good character – You must show that you have respected UK law and immigration rules.
2. English language requirement – You must pass an approved English test (unless exempt).
3. Life in the UK Test – You must pass the Life in the UK Test.
4. Residence – You must have lawfully lived in the UK for at least 3 years before the date of your application.
5. Presence in the UK – You must have been physically present in the UK exactly 3 years before the date of your application.
6. Free from restrictions – You must hold indefinite leave to remain (ILR), permanent residence, or settled status at the time of your application (no 12-month waiting period is required for spouses).
7. Absences over 3 years – You must not have spent more than 270 days outside the UK in the 3 years before your application.
8. Absences in the last year – You must not have spent more than 90 days outside the UK in the 12 months before your application.

Amira’s Route to British citizenship: Possible Solutions

Step 1 — Was Amira already British at birth?

• If she was born in the UK, she may already be British.
  At least one parent must have been British or settled at the time of birth.
  If that applies, she is British by birth and does not need to apply.
• If she was born outside the UK, different rules apply.
  She may be British by descent if one parent was British otherwise than by descent at her birth.
  This means the parent was British through birth, registration, or naturalisation.

If she wants to claim citizenship through her father and was born before 1 July 2006, special rules apply.
Before that date, the father’s marital status no longer matters.
This applies whether she was born in or outside the UK.

Step 2 — Could Amira qualify by registration (not automatic, application needed)?

• She is now over 18. If she was born in the UK and lived there for the first 10 years of life (with absence limits), then she may apply to register.
• If she is 18 or over and is affected by historical unfairness routes (because her father was not married to the child’s mother), then adult registration may be possible.
• If none apply, go to Step 3.

Step 3 — Naturalisation (adult route with ILR/settled status required)

• If she is married to / in a civil partnership with a British citizen, then she applies under s.6(2).
• If she is not married to a British citizen, then she applies under s.6(1).

She’ll need to meet all the relevant requirements of the intended application. .

What Amira should check next (to choose the right path)

• Place of birth and parents’ status at her birth → rules in Step 1.
• Her first 10 years’ residence (if born in the UK) → possible s.1(4) registration.
• Any historical-unfairness connection → adult registration.
• Marital status to a British citizen or if not, other rules should be satisfied → naturalisation under s.6(1) or s.6(2).

British Citizenship Routes in 2025 and Beyond

There are a number of tiny details that you need to check to establish if you qualify for British citizenship. Each has its own rules, and even small details, like a parent’s status at birth or time spent outside the UK, can make a big difference. That is why so many people, like Amira in our case study, feel unsure which route applies to them.

To make things clearer, I’ve created a British Citizenship Route Finder Flowchart. In one page, it shows you the key “yes/no” questions that lead to the right route: birth, descent, registration, or naturalisation. It also highlights where an application might stop, saving you time and money.

Instead of digging through pages of legal text, you’ll have a simple, visual tool to guide your next step.

This free tool is designed to give you clarity and confidence on your path to citizenship.