Applying for British citizenship by naturalisation is usually the final step for adults who have lived in the UK, obtained indefinite leave to remain, settled status or another qualifying permanent status, and now want to become British. The process is not automatic, even if you have lived in the UK for many years, and the Home Office will check your residence, absences, immigration history, English language ability, Life in the UK Test, good character and supporting documents.
Most applicants apply under the standard five-year route. If you are married to, or in a civil partnership with, a British citizen, you may be able to use the three-year route instead. The three-year route can be quicker, but it is not a shortcut around the main requirements. You still need the correct immigration status and must meet the legal tests at the date of application.
This guide explains the naturalisation process in practical terms, including eligibility, documents, fees, timings and common mistakes. If you are unsure whether your immigration history, absences or documents meet the requirements, Immigration Solicitors UK can help you assess your position before you submit an application.
What Is British Citizenship By Naturalisation?
Naturalisation is the route used by many adults who have already settled in the UK and want to become British citizens. It is different from registration, which is a separate nationality process often used for children or people with a specific statutory entitlement. Naturalisation is discretionary, meaning the Home Office must be satisfied that the legal requirements are met and that there are no reasons to refuse the application.
Holding indefinite leave to remain or settled status does not make you British. ILR and settled status allow you to live in the UK without a time limit, but British citizenship gives you nationality status, the right to apply for a British passport and the full civic rights that come with being British. A separate naturalisation application is required.
Who Can Apply For British Citizenship?
There are two main adult naturalisation routes. The correct route depends largely on whether you are married to, or in a civil partnership with, a British citizen at the time you apply.
The Standard Five-Year Route
The five-year route applies to most applicants who are not applying as the spouse or civil partner of a British citizen. You must usually have lived in the UK for at least five years before the application is received by the Home Office. You must also normally have held ILR, settled status or another form of unrestricted residence for at least 12 months before applying.
You must have been physically present in the UK exactly five years before the Home Office receives your application. This is a strict and commonly missed requirement. For example, if you apply online on 10 November 2026, you should check whether you were physically in the UK on 10 November 2021. If you were abroad on that date, it may be sensible to delay the application until the relevant date works in your favour.
The Three-Year Route For Spouses And Civil Partners
If you are married to, or in a civil partnership with, a British citizen, you may be able to apply after three years’ residence in the UK. You usually do not need to wait 12 months after obtaining ILR or settled status, but you must still hold the correct status at the time of application.
You must have been physically present in the UK exactly three years before the application is received. Marriage to a British citizen does not automatically make you British, and the Home Office will still assess residence, absences, good character, English language and Life in the UK requirements. If your immigration journey began through a partner route, our related article on how to apply for a UK spouse visa may also help you understand how partner-based immigration fits into the wider path to settlement and citizenship.
Naturalisation Eligibility Checklist
Before applying, it is worth checking each requirement carefully. Naturalisation fees are significant, and avoidable mistakes can lead to delay or refusal.
- You are aged 18 or over and have the mental capacity to understand the application.
- You have completed the relevant five-year or three-year qualifying residence period.
- You were physically present in the UK on the exact start date of that qualifying period.
- Your absences are within the usual limits, or you have strong reasons for requesting discretion.
- You hold ILR, settled status or another qualifying form of unrestricted residence.
- You have complied with UK immigration laws during the relevant period.
- You meet the English language requirement, unless exempt.
- You have passed the Life in the UK Test, unless exempt.
- You meet the good-character requirement.
- You can provide two suitable referees.
If you have not yet reached the settlement stage, you may need to apply for ILR or another qualifying status first. You can read more about that stage on our settlement application guidance page.
Residence And Absence Requirements
The Home Office calculates the qualifying residence period backwards from the date it receives your application. For online applications, this is usually the date you submit the form. You should check your travel history before pressing submit, rather than afterwards over a worried cup of tea.
For the standard route, the usual maximum absence is 450 days during the five-year qualifying period, with no more than 90 days in the final 12 months. For the spouse or civil partner route, the usual maximum is 270 days during the three-year qualifying period, again with no more than 90 days in the final 12 months.
The final-year limit is separate from the total absence limit. You could be within the overall total but still have too many days outside the UK in the last year. You should count full days of absence carefully using passport stamps, flight records, employer records, previous visa applications and any personal travel records you hold.
The Home Office can exercise discretion in some cases where absences exceed the usual limits, but discretion should never be assumed. The reasons for travel, the extent of your UK home, family and employment ties, and the overall strength of your evidence may all matter. If your absences are high, a tailored legal assessment is usually worthwhile before applying.
English Language And Life In The UK Requirements
Most applicants must show sufficient knowledge of English, Welsh or Scottish Gaelic and must also pass the Life in the UK Test. These are two separate requirements. Passing the Life in the UK Test does not prove English language ability, and an English qualification does not replace the Life in the UK Test.
English language evidence may include an accepted Secure English Language Test, a qualifying degree taught or researched in English, or nationality from a listed majority English-speaking country. Some applicants are exempt, including those aged 65 or over and those with a qualifying long-term physical or mental condition supported by appropriate evidence.
The Life in the UK Test currently costs £50 and must be booked through the official service. If you passed it when applying for ILR, you generally do not need to take it again, but you should keep the reference or evidence. The official Home Office guidance on Form AN naturalisation requirements should always be checked before applying, because evidence rules and exemptions can change.
The Good-Character Requirement
The good-character requirement is broader than many applicants expect. It is not limited to serious criminal convictions. The Home Office may consider cautions, driving offences, fixed penalties, immigration breaches, deception, unpaid taxes, bankruptcy issues, previous refusals and whether information has been fully disclosed.
The safest approach is to answer every question honestly and provide explanations where needed. Omitting a conviction, caution or previous immigration issue can create a bigger problem than the issue itself, because the Home Office may treat non-disclosure as dishonesty. If you are worried about an old matter, get advice before submitting rather than hoping it will be overlooked.
Documents Needed For A Naturalisation Application
The exact documents depend on your route and circumstances, but most applicants should prepare evidence in organised categories. A strong application makes it easy for the Home Office to see how each requirement is met.
- Current and previous passports or travel documents.
- Evidence of ILR, settled status or other qualifying permanent status.
- Documents showing residence and physical presence in the UK.
- Travel history and absence records.
- English language evidence, unless exempt.
- Life in the UK Test evidence, unless exempt.
- Marriage or civil partnership evidence, if applying under the three-year route.
- Documents explaining any criminal, civil, tax or immigration issues.
- Two completed referee declarations.
Adult applicants normally need two referees. Each should usually have known you for at least three years. One should normally be a professional person, and the other should usually hold a British citizen passport and either be a professional person or be aged over 25. Always check the current referee guidance because the Home Office can reject unsuitable referee evidence.
How To Apply For British Citizenship Step By Step
The application is usually made online using Form AN. Before starting, decide whether you are applying under the five-year route or the spouse or civil partner three-year route. Check your permanent status, physical-presence date and absences before completing the form.
- Confirm that you meet the correct route and residence requirements.
- Calculate all absences from the UK during the qualifying period and final year.
- Gather documents and check that names, dates and passport details are consistent.
- Complete the online naturalisation application carefully.
- Pay the current Home Office fee.
- Upload supporting documents or arrange scanning where available.
- Attend your biometric appointment and provide fingerprints and a photograph.
- Respond promptly if the Home Office asks for more information.
- Wait for the decision and, if approved, attend the citizenship ceremony.
The Home Office fee changes periodically, so check the current fee immediately before applying. Where the published fee includes both the application fee and the citizenship ceremony fee, make sure you budget for the full amount. Biometrics are normally required and should generally be enrolled within the period specified by the Home Office, commonly within 45 days of submitting the application.
For applicants who want support with eligibility, document preparation or a full application review, our British citizenship application service explains how professional guidance can help reduce avoidable errors.
How Long Does British Citizenship Take?
The Home Office usually aims to decide naturalisation applications within six months, although this is not guaranteed. Straightforward applications may be decided within the target period, while complex cases can take longer if further checks are needed.
Delays can be caused by missing documents, unclear travel history, inconsistent personal details, unresolved good-character issues, delayed biometrics or requests for further information. Keeping copies of everything submitted and monitoring your email carefully can help avoid unnecessary complications.
What Happens After Approval?
If your application is approved, you are not fully finished until you attend the citizenship ceremony. Adult applicants normally take an oath or affirmation of allegiance and make a pledge. You will usually receive your certificate of British citizenship at the ceremony.
You must normally attend the ceremony within three months of receiving the Home Office invitation. After the ceremony, you can apply separately for a British passport. The passport process is not part of the naturalisation application, so you should follow the current passport guidance when you reach that stage.
The UK generally permits dual nationality, but your existing country of nationality may not. Before naturalising, check whether becoming British could affect your other citizenship, property rights, military obligations or consular protection.
Common Reasons Applications Are Refused Or Delayed
Common problems include applying under the wrong route, failing the physical-presence rule, exceeding absence limits without a strong explanation, applying too early after ILR under the standard route, missing English or Life in the UK evidence, unsuitable referees, incomplete disclosure or failing to attend biometrics.
If a naturalisation application is refused, there is not a simple ordinary appeal on the merits. Depending on the reason, you may need to correct the problem and reapply, request reconsideration where appropriate, or consider a legal challenge if there has been an arguable public law error. The right next step depends on the refusal reasons.
Frequently Asked Questions
Can I apply for British citizenship after ILR?
Yes, ILR is commonly the permanent-status stage before naturalisation, but you must also meet the residence, absence, English language, Life in the UK and good-character requirements.
Can I apply for citizenship immediately after getting ILR?
Under the standard five-year route, you usually need to have been free from immigration restrictions for 12 months. If you are married to or in a civil partnership with a British citizen, that 12-month wait usually does not apply, provided you meet the other requirements.
How many days can I be outside the UK for naturalisation?
The usual limit is 450 days over five years for the standard route, or 270 days over three years for the spouse or civil partner route. Both routes also usually require no more than 90 days’ absence in the final 12 months.
Do I need to take the Life in the UK Test again?
If you have already passed the Life in the UK Test, you generally do not need to retake it for naturalisation. You should keep your pass reference or evidence and ensure it is correctly included in the application.
Can I keep my existing nationality after becoming British?
The UK allows dual nationality, but not every country does. You should check the law of your current country of nationality before applying for British citizenship.
