British citizenship by naturalisation
How can people who move to and settle in the UK become British citizens?
Foreign residents who wish to become British citizens can apply for ‘naturalisation’. This is the citizenship process for adults who have permanent residence (indefinite leave to remain) in the UK.
The rules on naturalisation are in the British Nationality Act 1981. The legislation also allows for citizenship by birth or through the process of registration, which this briefing does not cover.
In addition to indefinite leave to remain, the person needs to have lived in the UK for five years (or three if married to a British citizen), demonstrate language ability, pass a citizenship test and be of good character.
At time of writing the application fee is around £1,800, of which £130 covers the cost of a mandatory citizenship ceremony if approved. Ceremonies are arranged by local councils and involve a pledge of a loyalty to the country and an oath to the King.
In 2025, there were almost 167,000 grants of citizenship by naturalisation. Around a quarter were people from South Asia (including India and Pakistan), while another fifth were from European Union countries such as Italy, Romania and Poland.
The citizenship rules have not changed significantly over the past ten years, although the fees have increased. But the government wants to make it harder to qualify for indefinite leave to remain (‘earned settlement’), which would have a knock-on impact on the pathway to naturalisation.
There has also been some recent controversy over denying citizenship to refugees whose original journey to the UK was by small boat or lorry, which is usually considered evidence that they may not be of good character.
Naturalised citizens have the same rights as people born with British citizenship. The UK permits dual nationality, meaning that it does not force naturalised citizens to renounce their original citizenship (although the other country’s law may require this). But the Home Office does expect most people with British citizenship to travel to the UK on a British passport, which has caused some complaints.