People often use the words citizenship and naturalisation as if they mean the same thing, and the distinction matters more than it first appears. British citizenship is a legal status. Naturalisation is one of several routes by which an adult can acquire that status. Choosing the wrong route, or assuming the wrong requirements apply, can delay an application or lead to a refusal. This post provides an overview of the difference between citizenship and naturalisation for a UK nationality application.
What is British citizenship under UK law?
British citizenship is a legal status conferred by the British Nationality Act 1981, describing a person’s relationship with the United Kingdom rather than the route by which it was acquired. A British citizen holds the right of abode, is free from immigration control, and is entitled to hold a British passport and to register to vote.
The status is the same regardless of how it was obtained. A person who is British from birth and a person who naturalised as an adult hold identical citizenship. What differs between them is not the status but the legal route that led to it.
What is naturalisation under UK nationality law?
Naturalisation is the discretionary grant of British citizenship to an adult who is not already British and who meets the statutory requirements. It is governed by section 6 of the British Nationality Act 1981 and is the most common route to citizenship for long-term residents who came to the UK as adults. An applicant naturalises by making an application on form AN, examined in the Form AN guide.
Naturalisation is a process, not a status. A successful application results in the status of British citizenship. A person must be aged 18 or over to naturalise.
What is the difference between citizenship and naturalisation?
The difference is that citizenship is the destination and naturalisation is one road to it. British citizenship is the legal status a person holds. Naturalisation is the application process through which an eligible adult acquires that status, where they were not British at birth or by an earlier route.
Every person who naturalises becomes a British citizen, but not every British citizen has naturalised. A person born British, or British by descent, or who acquired citizenship as a child by registration, holds the same citizenship without ever having naturalised. Understanding which route applies to a given person is the practical reason the distinction matters, because each route carries different requirements and a different application form.
How else can a person become a British citizen?
British citizenship can be acquired by several routes besides naturalisation, depending on a person’s circumstances and date of birth. The principal routes are birth in the UK to a qualifying parent, descent from a British parent, adoption, registration, and naturalisation. Some people also acquire the status automatically where the statutory conditions are met, as explained in the guide on automatic acquisition of British citizenship.
Registration and naturalisation are often confused because both are application routes. Registration is generally the route for children and for certain adults with a specific statutory entitlement. Naturalisation is the discretionary route for adults who do not have such an entitlement. The route that applies determines the form, the fee and the requirements.
Who can apply to naturalise?
An adult can apply to naturalise where they are settled in the UK, meet the residence requirement, and satisfy the good character, language and knowledge requirements. The British Nationality Act 1981 provides two main bases. Section 6(1) applies to applicants who are not married to or in a civil partnership with a British citizen. Section 6(2) applies to those who are.
The two bases differ chiefly in the residence requirement and in when settlement is needed. An applicant under section 6(1) must ordinarily have held indefinite leave to remain or settled status for at least 12 months before applying. An applicant under section 6(2), as the spouse or civil partner of a British citizen, may apply as soon as they hold settled status, without that further 12-month wait. The route to citizenship after settlement is set out in the guide on applying for British citizenship after ILR.
What are the requirements to naturalise?
The requirements to naturalise are residence, good character, knowledge of language and life in the UK, and, for section 6(1) applicants, an intention to continue living in the UK. The residence requirement turns on a continuous qualifying period in the UK and on limits to the time spent absent during that period. The qualifying period is five years for section 6(1) applicants and three years for section 6(2) applicants.
The good character requirement considers a person’s conduct, including any criminal history, immigration history and financial conduct such as unpaid tax or NHS debt. The knowledge requirement is met by passing the Life in the UK Test and by demonstrating English at the required level, addressed in the guide on the English requirement for citizenship and settlement. The detail of the residence and absence rules is examined in the guide on residence requirements for naturalisation.
Is naturalisation guaranteed where the requirements are met?
Naturalisation is not guaranteed even where the formal requirements appear to be met, because it is a discretionary grant. Section 6 of the British Nationality Act 1981 provides that the Home Secretary may grant a certificate of naturalisation to a person who meets the requirements. The word may, rather than must, is the source of the discretion.
In practice, an application that clearly meets the residence, good character, language and knowledge requirements is well placed. The discretion is most often engaged by the good character requirement, which is assessed broadly and is not confined to criminal convictions. An application may be refused where a good character concern arises, even where every other requirement is satisfied.
Do children naturalise or register as British citizens?
Children do not naturalise. A child who is not British acquires citizenship by registration rather than by naturalisation, because naturalisation is confined to adults aged 18 or over. Registration covers children with a statutory entitlement and children for whom the Home Secretary may register at discretion.
The distinction matters for families applying together, where the adults naturalise and any non-British children register. The two routes use different forms and carry different requirements, even where the family applies at the same time.
Frequently asked questions
No. Naturalisation is the legal process by which an eligible adult becomes a British citizen. British citizenship is the legal status that results from a successful application. The process and the status are distinct, and a person can hold the status without ever having gone through the naturalisation process.
Yes. Many British citizens acquired the status by birth, by descent from a British parent, or by registration as a child. None of these routes involves naturalisation, yet each results in full British citizenship.
No. Naturalisation is a discretionary grant under section 6 of the British Nationality Act 1981. An application can be refused even where the residence, language and knowledge requirements appear to be met, most commonly on good character grounds.
Naturalisation is the discretionary route to citizenship for adults. Registration is the route for children and for certain adults who have a specific statutory entitlement to be registered. The correct route depends on the applicant’s age and circumstances.
The qualifying period is ordinarily five years for an applicant who is not married to a British citizen, and three years for the spouse or civil partner of a British citizen. Limits also apply to the number of days the applicant may have spent outside the UK during that period.
How Whytecroft Ford can help
The Whytecroft Ford immigration team advises applicants across the naturalisation route, from confirming the correct basis of application to preparing the residence calculation and addressing good character. The team works through absences, qualifying dates and the supporting evidence so that the application reflects the applicant’s full circumstances. This is particularly valuable for the settled resident approaching the end of the qualifying period who wants the application made correctly the first time. To discuss your application with our team, call 0208 757 5751 or use the contact form.
Sources
- Section 6, British Nationality Act 1981 – legislation.gov.uk
- Become a British citizen by naturalisation – GOV.UK
Written and reviewed by the Whytecroft Ford immigration team. IAA Accredited. All guidance is researched against primary sources, including the British Nationality Act 1981, Home Office caseworker guidance and GOV.UK. Reviewed every six months, or sooner following a rule change. Last reviewed: 10 June 2026.
