About the British Citizenship Practice
~7 min read · Updated April 2026
British citizenship by naturalisation is the final step for most adult migrants who already hold Indefinite Leave to Remain (ILR). Once granted, you can hold a British passport, vote in all UK elections, stand for public office and pass citizenship to your children born outside the UK. The Home Office charges £1,630 in 2026 (adult application) and decisions usually take three to six months.
This guide covers exactly what the Home Office checks, the residency maths most applicants get wrong, and what happens at the citizenship ceremony. Use the practice questions below to lock in the facts you'll need both for the Life in the UK Test and for any interview the Home Office may request.
Who qualifies for naturalisation
You must be 18 or over, of sound mind and 'good character' (no recent unspent convictions, no immigration breaches, paid taxes). You'll normally need ILR or settled status held for at least 12 months — unless you're married to a British citizen, in which case there's no 12-month wait.
Residency: at least five years lawfully in the UK before the application date (three if married to a British citizen), with no more than 450 days outside the UK in those five years (270 if the three-year route) and no more than 90 days outside in the final 12 months.
Knowledge of life and language
You must pass the Life in the UK Test (24 questions, 18 to pass, £50). You also need to prove English at CEFR B1 or above — usually with a Secure English Language Test (SELT) certificate or a degree taught in English. People over 65 are exempt from both.
Both certificates are kept by you and uploaded with the AN form. They have no expiry for citizenship purposes once issued.
The application — Form AN
Apply online at gov.uk using Form AN. You'll need two referees (one professional, one British citizen who has known you 3+ years), your passport, BRP, Life in the UK certificate, English evidence and a complete travel history for the qualifying period — to the day.
The biggest cause of refusal is missing or wrong absence dates. Get them from your passport stamps, airline emails and the new ETA / EES record before you start. A single overlooked trip can fail the residency requirement.
The citizenship ceremony and oath
If approved, you have 90 days to attend a ceremony at your local council. You take an Oath of Allegiance to the King (or a non-religious Affirmation) and a Pledge to the UK, then receive your naturalisation certificate. Only after the ceremony can you apply for a British passport.
Ceremonies are usually small group events; you can bring two guests. Smart dress is expected. The council fee (£80) is included in the £1,630 application charge.
Common reasons for refusal
Failing the good-character test (recent driving offences, unpaid council tax, undeclared cash work). Exceeding absence limits. Incorrect referee details. Forgetting to update HMRC after a name or address change. The Home Office cross-checks DWP, HMRC and police records — declare everything.
If refused you can request a reconsideration (£372) within 28 days. Most successful reconsiderations turn on new evidence rather than legal argument.
Documents and evidence checklist
Before you start the AN form, gather: a current passport (and every previous passport covering the qualifying period), your BRP or eVisa share code, the original Life in the UK pass letter, your B1 English certificate or a degree certificate with transcript, three months of council tax or utility bills as proof of address, and a payslip or HMRC tax summary covering the qualifying years.
If you've changed name (marriage, deed poll), include the legal change document plus any old passports in the previous name. Missing documents are the second-biggest cause of refusal after absence miscalculations — caseworkers will not chase you, they simply refuse.
Spend an evening cross-checking your travel history against passport stamps, e-gate records, airline emails and bank card transactions abroad. The Home Office runs the same cross-check; even a forgotten three-day weekend in Dublin counts toward the 450-day absence limit.
Costs, timelines and what happens next
Total realistic spend: £1,630 application + £50 Life in the UK Test + £150–£200 SELT English test + £25–£35 biometrics enrolment at a UKVCAS service point. Budget around £1,900 end to end. Children added under 18 cost £1,214 each.
After submission you book a biometrics appointment within 45 days. Most decisions land in three to six months by email. If approved, the Home Office sends an invitation to the citizenship ceremony at your local council; you must attend within 90 days. Your naturalisation certificate is issued at the ceremony — keep it safe, it's the only document HM Passport Office accepts to issue your first British passport (£94.50 in 2026).
You become a British citizen the moment you take the Oath, not the moment the Home Office approves the application. Until the ceremony you're still on ILR.
Practising for the citizenship interview
Most adult naturalisation applications are decided on paper. A small number — usually where the caseworker has questions about character, identity or residency — are called for an interview at a regional Home Office centre. Questions are conversational and cover your application content: dates of trips abroad, employment history, family details, and basic Life in the UK material.
Use our practice questions to refresh the Life in the UK content in the months between passing the test and submitting the AN form. Caseworkers occasionally drop in informal questions like 'who is the current monarch?' or 'when is St George's Day?' to confirm the test was your own work, so don't let that knowledge fade.
Ready to start?
You've read the guide — now put it into practice. 45 of 45 mock papers ready, each with 24 questions and full explanations.
Start British Citizenship Practice