UK Naturalisation and Citizenship Application
Naturalisation is how you become a British citizen after holding a settled status such as indefinite leave to remain (ILR). It is often confused with ILR itself. This guide sets out the two routes, the day-count rules, the cost and the timing. Based on the official GOV.UK guidance (gov.uk/apply-citizenship-indefinite-leave-to-remain), September 2026.
Citizenship, not residence
ILR is a residence status; naturalisation is acquiring British citizenship. For most people the order is: get ILR, then apply for citizenship. The rules below are the application side.
The two routes
1. The 5-year route
- You are 18 or over.
- You have held ILR, settled status or indefinite leave to enter for at least 12 months.
- You can prove you were in the UK exactly 5 years before the day your application reaches the Home Office.
2. The spouse or civil partner route (3 years)
- You are 18 or over and married to, or in a civil partnership with, a British citizen.
- You have lived in the UK for 3 years.
- You can apply as soon as you get ILR — there is no 12-month wait.
- You can prove you were in the UK exactly 3 years before the application reaches the Home Office.
How many days you can be away
| 5-year route — total | No more than 450 days in the 5 years |
| 5-year route — last 12 months | No more than 90 days |
| 3-year spouse route — total | No more than 270 days in the 3 years |
| 3-year spouse route — last 12 months | No more than 90 days |
Diplomats and visiting armed forces have special treatment. Pre-settled status has a special case too.
Other requirements
- English, Welsh or Scottish Gaelic language ability.
- Pass the Life in the UK test.
- Be of good character.
- Intend to continue living in the UK.
Cost and timing
- Fee £1,839 (£1,709 application + £130 ceremony).
- Biometrics are free.
- A decision usually takes about 6 months.
Long absence and existing ILR
If you already hold ILR, a long absence can end it: more than 2 continuous years outside the UK, Channel Islands and Isle of Man generally means you lose it (5 continuous years for EU settled status; 4 for Swiss citizens and their families). Returning after that may need a Returning Resident visa.
Related: passport photo validity, the UK immigration ID Check app, the UK visa documents checklist, passport name change, or prepare a photo with the UK passport photo tool.
Frequently asked questions
Is naturalisation the same as indefinite leave to remain?
No. Indefinite leave to remain (ILR) is a residence status; naturalisation is how you become a British citizen. Most people get ILR first, then apply for citizenship.
How long must I have lived in the UK?
On the 5-year route you need ILR, settled status or indefinite leave to enter for at least 12 months. If you are married to or in a civil partnership with a British citizen, the route is 3 years and you can apply as soon as you get ILR — without the 12-month wait.
How many days can I be away from the UK?
On the 5-year route: no more than 450 days in the 5 years and no more than 90 days in the last 12 months. On the 3-year spouse route: no more than 270 days in the 3 years and no more than 90 days in the last 12 months.
What is the “in the UK 5 years ago” test?
You must have been in the UK exactly 5 years (or 3 years on the spouse route) before the day your application reaches the Home Office. There are limited exceptions.
How much does it cost and how long does it take?
It costs £1,839 — £1,709 for the application plus £130 for the ceremony. Biometrics are free, and a decision usually takes about 6 months.
Can I lose my status if I stay away too long?
Yes. You can lose indefinite leave to remain if you are outside the UK, the Channel Islands and the Isle of Man for more than 2 continuous years (5 years for EU settled status, 4 for Swiss citizens and their families).
Source: GOV.UK, "Apply for citizenship if you have indefinite leave to remain or settled status" and the spouse/civil partner page — retrieved 2026-09-29. Rules and fees change, so confirm the current position on the official page before you apply.