British citizenship requirements: naturalisation explained

In brief

To naturalise as a British citizen you must have completed a residence period in the UK, normally five years, or three if you are married to or the civil partner of a British citizen, kept your absences within the permitted limits, held indefinite leave to remain or settled status for the required period, met the English language and Life in the UK requirements, and be assessed as being of good character. The fee is £1,735 per adult and the Home Office service standard is up to six months.

The requirements, in the order they are assessed

Each is evidenced separately, and any one of them can decide the application.

Five-year route or three-year spouse route

The route you use changes the residence period, the absence limits and whether you wait after ILR.

Residence period

5 years standard, 3 years if married to a British citizen

Total absence limit

450 days over 5 years, 270 days over 3 years

Final-year absences

No more than 90 days on either route

Wait after ILR

12 months standard, none on the spouse route

Immigration control

No breach of conditions during the period

Documents to have ready

Assemble the evidence first: the application locks to the date you submit and pay.

• Current passport, plus every passport covering the residence period
• ILR, settled status or permanent residence evidence
• A dated list of every absence from the UK, with reasons
• English language evidence: test certificate, degree or nationality
• Life in the UK test pass reference
• Residence evidence: payslips, tax records, council tax or tenancy history
• Spouse route: marriage or civil partnership certificate and your partner’s British passport
• Details of any convictions, cautions, civil judgments or immigration breaches
• Two referees who meet the published requirements

Referees are a formal requirement, not a formality: one must normally be a professional person and one a British citizen over 25 who has known you for at least three years, and neither can be a relative, your solicitor or a Home Office employee.

Fees, timing and the ceremony

One fee per applicant, then a ceremony before the certificate is issued.

Adult naturalisation

£1,735 including the ceremony fee

Registering a child

£1,214

Service standard

Up to six months from biometrics

Priority service

Not available for naturalisation

Ceremony

Attend within three months of the invitation

We review the residence and absence record, the good character position and the language and test evidence before an application is submitted, so that an absence overrun or an unspent conviction is identified while waiting is still an option.

How an application is actually assessed

The residence and absence checks come first, because everything else depends on them.

A caseworker first checks that the residence period claimed is supported by the passport stamps, travel history and any Home Office record of your immigration status, then checks that your absences fall within the applicable limit. Only once residence is confirmed does the case move on to settlement status: did you hold ILR, settled status or permanent residence for the required period before applying, and was that status still valid throughout.

Good character is checked separately and can override an otherwise strong residence record. The Home Office looks back at least ten years for immigration breaches such as overstaying, working without permission or using deception in a previous application, and further back for serious criminal matters. Civil penalties, unpaid council tax enforcement, bankruptcy and driving offences resulting in a conviction can all be relevant, even where they seem minor in isolation.

English language and Life in the UK evidence is checked last, largely because most applicants already hold valid evidence from their ILR application and it simply carries forward. Where it does not, for example because a test certificate has expired in the interim, this is one of the easier points to fix before applying rather than after a refusal.

Common mistakes and refusal triggers

Most refusals are avoidable with an accurate absence count and a clean disclosure.

• Miscounting the 450 or 270-day limit by using calendar years instead of the actual residence window
• Overlooking a short trip in the final 12 months that tips the 90-day limit
• Applying before 12 months of ILR have passed on the standard route, rather than the spouse route
• Failing to disclose a caution, fixed penalty or minor conviction that no longer feels relevant
• Not explaining a period of overstaying or a previous refusal that shows on the Home Office record
• Referees who do not meet the published criteria, for example a relative or a professional contact of less than three years
• An English or Life in the UK certificate that has lapsed in the gap since the ILR application

Dependants, transitional cases and other edge cases

Children, older cases and EU Settlement Scheme histories often need a different approach.

Children under 18 cannot naturalise; they are registered as British citizens instead, under a separate and cheaper process with its own criteria, most commonly because a parent becomes British or because the child has lived in the UK for a set number of years. If your family circumstances are mixed, for example a British parent and a child born before the parent naturalised, check the registration route before assuming the child needs to wait for their own residence period.

People who obtained settled status under the EU Settlement Scheme can naturalise once the residence and absence conditions are met, counting residence from before the scheme existed provided it was lawful under free movement rules at the time. Absences taken before the pandemic-related easements were withdrawn should still be checked against the standard limits, since those easements no longer apply to new applications.

Long-standing UK residents who once held indefinite leave to remain but let it lapse through an absence of more than two years need to re-establish settlement before they can naturalise, which usually means a fresh ILR application first. Anyone with a historic deportation order, exclusion decision or unresolved immigration enforcement matter should take advice before applying, since these can be a bar regardless of how long ago they arose.

Who to contact next

A residence and absence check before you apply is the single most useful step.

Use the UK Absences Calculator to confirm your total and final-year absences against the 450 and 90-day limits, or the 270 and 90-day limits on the spouse route, before you commit to a submission date. Where the good character position is not straightforward, for example a spent conviction, a past immigration breach or a tax or benefits query, a review of the disclosure before you apply is worth the time, because there is no appeal if the application is refused.