UK Citizenship Eligibility Calculator

British citizenship through naturalisation requires at least 12 months of ILR, unless you are married to a British citizen, in which case you can apply as soon as you hold ILR. You must have lived in the UK for at least 5 years, or 3 years if married to a British citizen, pass the Life in the UK test and meet the English language requirements. Settled status counts in the same way as ILR for the 12-month qualifying period.

The residency requirement includes not being absent for more than 450 days in the 5 years before the application, and not more than 90 days in the 12 months before it. Applicants married to a British citizen need 3 years of residence instead, with no more than 270 days outside the UK in that time and 90 in the final 12 months. The calculator checks these thresholds against your travel history and shows the earliest date you can apply.

Sitting alongside residence are conditions that are harder to measure with a calendar. Good character covers criminal convictions, where any prison sentence is usually disqualifying, along with immigration breaches and fraud. You also need to be of sound mind and to intend to go on living in the UK. Those are the grounds on which otherwise well-prepared applications tend to come unstuck.

Naturalisation costs £1,709, with a £130 ceremony fee on top, so £1,839 whether you apply by marriage or on the standard route, and spouses applying together pay £1,709 each. Registering a child costs £1,000 from 8 April 2026. Adding the £50 Life in the UK test and an English test at £160 to £182 puts a typical adult application between £2,049 and £2,071.

This calculator works out when you can apply, 12 months after ILR, and the cost of the citizenship application itself, the ceremony and any tests still needed. The earlier stages of a typical route cost far more. Someone arriving on a three-year Skilled Worker visa pays £819 plus £3,105 of surcharge at the outset, then £3,226 for ILR with about £210 of tests at year 5, and £1,709 for citizenship at year 6 with £130 for the ceremony, which comes to roughly £9,199 before any visa extensions along the way.

The Life in the UK test is a 45-minute computer-based exam sat at one of more than 30 centres, with 24 multiple choice questions and a pass mark of 75%, meaning 18 correct. Questions range across British history from the Tudors and the Empire to the World Wars and the 20th century, culture and sport, Parliament, voting and devolution, the legal system, and the calendar of festivals and holidays. The official handbook costs £12 to £14. About 80% of candidates pass, with a higher failure rate among non-native English speakers, and a resit costs £50 with no limit on attempts.

English at B1 on the CEFR scale is proved by IELTS Life Skills B1, Trinity GESE Grade 5, LanguageCert International ESOL B1 or Pearson PTE Academic UKVI at 51 or above, costing £160 to £182 and valid for 2 years. Applications go in online through gov.uk and usually take 6 to 12 months, occasionally as long as 24, with a biometrics appointment 2 to 4 weeks after submission. A ceremony follows within 3 months of approval, where you take the Oath of Allegiance and receive the certificate. A British passport then costs £102 online and takes about 3 weeks.