Applying for British Citizenship by Naturalisation - 2025 Guidance

Naturalisation is the most common route for adults to become British citizens. It is a formal legal process under the British Nationality Act 1981, and unlike some immigration applications, it is not a right but a discretionary decision made by the Home Secretary. Applicants must meet a number of strict requirements to be considered eligible.

If you have held Indefinite Leave to Enter (ILE), Indefinite Leave to Remain (ILR), or Settled Status for at least 12 months, and you meet other requirements, such as residence requirement, intention to live in the UK requirement, good character requirement, and English language and the Life in the UK requirements, you may be eligible to apply.

Becoming a British citizen through naturalisation does not automatically grant you a British passport. If your application is approved, you will receive a Certificate of Naturalisation and must attend a citizenship ceremony, during which you will take an oath or affirmation of allegiance. Only after completing these formalities can you apply for your first British passport.

Naturalisation brings long-term stability, particularly with the introduction of the UK eVisa system. However, the process is technical, and mistakes or missing information can result in refusal. Applicants must demonstrate continuous lawful residence in the UK for a qualifying period of either five years or three years (if married to a British citizen).

Below is an overview of the key eligibility requirements for naturalisation:

What are the Requirements of Naturalisation under the British Nationality Act 1981?

The legal requirements under Section 6(1) of the British Nationality Act 1981 that the Applicant must meet in order to succeed in their application are as follows:

• They are aged 18 or over at the date of application;
• They are of sound mind, so that they understand the step they are taking;
• They intend to continue living in the UK;
• The Applicant is a person of Good Character;
• They meet the English Language requirement;
• The Applicant has sufficient knowledge about the Life in the UK;
• The Applicant was in the UK at the beginning of the period of five years ending with the date of the application, and that the number of days on which he was absent from the United Kingdom in that period does not exceed 450; and
• The number of days on which the Applicant was absent from the United Kingdom in the period of twelve months so ending does not exceed 90; and
• The Applicant was not at any time in the period of twelve months so ending subject under the immigration laws to any restriction on the period for which he might remain in the United Kingdom; and
• The Applicant was not at any time in the period of five years so ending in the United Kingdom in breach of the immigration laws.

How Much to Naturalise as a British Citizen?

As of May 2025: 

• £1,735 per adult naturalisation application (including £130 for ceremony fee)
• £1,214 per child for registration (not covered by this page)
• £50 Life in the UK Test (booked separately)
• £150-£170 for English Language test