British citizenship by naturalisation allows settled migrants to become British citizens and secure the full rights of British nationality.
Once naturalised, you may apply for a British passport, vote in UK elections, and live in the United Kingdom without immigration restrictions.
Most applicants become eligible after obtaining Indefinite Leave to Remain or settled status and then meeting the relevant residence, absence and good character requirements.
Naturalisation applications are made using Form AN and assessed in accordance with the British Nationality Act 1981 and current Home Office nationality Form AN guidance.
This guide explains:
• who can apply for British citizenship by naturalisation
• the main residence requirements
• absence limits and timing rules
• the good character requirement
• the application process and fees
• common reasons for refusal
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British citizenship by naturalisation is the process by which a non-British adult becomes a British citizen after meeting the legal requirements for nationality.
It is the most common route for migrants who have already settled in the UK through:
Once naturalisation is approved and the citizenship ceremony has been completed, the applicant becomes a British citizen in full.
Most adults can apply for British citizenship by naturalisation if they:
Naturalisation is not the same as registration. It is the main citizenship route for settled adults who were not automatically British.
The residence rules depend on whether you are married to or in a civil partnership with a British citizen.
Most applicants must show that they:
Applicants married to, or in a civil partnership with, a British citizen normally need to show that they:
Unlike the standard route, spouses and civil partners of British citizens do not usually need to wait 12 months after getting ILR or settled status before applying.
Absence limits are one of the most important parts of a naturalisation application.
Most applicants should not have spent:
Applicants in this category should not have spent:
The Home Office can exercise discretion in some cases, but applicants should not assume it will. Residence and travel history should be checked carefully before submission.
All applicants for British citizenship by naturalisation must satisfy the good character requirement.
The Home Office may consider a range of factors, including:
This is one of the most important parts of a naturalisation application, and refusals often arise where applicants underestimate how widely the Home Office can assess character.
Most applicants must meet the Knowledge of Language and Life in the UK requirement.
This usually means:
Applicants who previously met these requirements for Indefinite Leave to Remain will often already have the evidence they need, but it should still be checked carefully before applying.
Applications for naturalisation are usually made online using Form AN.
The process normally involves:
After the ceremony, the applicant receives a certificate of British citizenship and can then apply for a British passport.
If you want expert advice about the options available to you or if you are preparing your application and want access to First Migration's knowledge and experience, this is the service for you.
If you want to prepare your own application, why not take advantage of our Document and Application Review Service. Our specialist team can ensure your application is correctly prepared and all supporting documents meet the requirements for your application to be approved.
Our Full Consultancy Service is for clients looking for an end to end service where we take care of the full application process. We'll provide document lists and templates, complete the application forms and take care of everything else for you.
Our Priority Consultancy Service provides you with all the benefits of the Full Consultancy Service plus we will prepare and submit your application within 48 working hours of receiving all the supporting documents for your application.
Naturalisation applications are usually decided within 6 months, although some cases take longer where additional checks or further information are required.
Applicants should ensure that all documents and travel history details are accurate when applying, as inconsistencies can delay a decision.
The current Home Office fee for naturalisation as a British citizen is £1,839, which includes the citizenship ceremony fee (£1,709 for the application fee & £130 for the Citizenship Ceremony, as of April 2026).
Because fees can change, applicants should always check the latest Home Office fee before submitting the application.
Many clients choose First Migration for our history of excellent service and track record of success. However, we feel our greatest strength, and what makes us truly unique, is our small dedicated team that offers a truly personalised service. We genuinely love what we do, and our team relishes making a difference to the lives of our clients.
The exact documents required depend on the applicant’s circumstances, but most applications will include:
Where residence history is complex, applicants should also keep records to support their travel dates and physical presence in the UK.
If the application is approved, the applicant will usually be invited to attend a citizenship ceremony.
At the ceremony, the applicant makes an oath or affirmation and receives their certificate of British citizenship.
After this, they may:
Naturalisation applications may be refused for several reasons, including:
Because naturalisation is a nationality application rather than a visa extension, the Home Office expects high accuracy and full disclosure.
British citizenship applications require careful preparation, especially where there are:
• complex absences from the UK
• concerns about the good character requirement
• previous immigration issues
• questions about when to apply
At First Migration, we assist with:
• eligibility assessments
• residence and absence reviews
• document preparation
• application form checking and preparation
British citizenship by naturalisation is the legal process by which a settled adult becomes a British citizen after meeting the residence, good character and knowledge of language and life in the UK requirements.
Most applicants need 5 years of residence in the UK and must usually have held ILR or settled status for 12 months. If you are married to or in a civil partnership with a British citizen, the normal residence period is 3 years, and you can usually apply immediately after getting ILR or settled status. You need to live in the UK before applying for British citizenship.
Usually no. Most applicants must wait 12 months after getting ILR before applying. However, applicants married to or in a civil partnership with a British citizen can usually apply as soon as they have ILR, provided they meet the residence requirements.
Most applicants should not have spent more than 450 days outside the UK in the last 5 years and no more than 90 days in the last 12 months. Spouses and civil partners of British citizens should normally not exceed 270 days in 3 years and 90 days in the last 12 months.
The good character requirement means the Home Office must be satisfied that the applicant has respected UK laws and responsibilities. This can include reviewing criminal history, immigration breaches, deception, financial conduct and other relevant behaviour.
British citizenship applications are usually decided within 6 months, although some cases may take longer if the Home Office requires additional information or further checks.
The current Home Office fee is £1,839, including the citizenship ceremony fee. As fees can change, applicants should always check the latest Home Office fee before applying.
Yes. Applications can be refused if the applicant does not meet the residence, good character or documentation requirements, or if the Home Office believes the legal test for naturalisation has not been met.
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