British Naturalisation is the most common way by which a person with foreign citizenship can apply for British citizenship. If you are naturalised as a British citizen, you will be able to live and work in the UK without being subject to immigration control.
Unless you have a claim to British citizenship based on your ancestry (British citzenship by descent), you will need to apply for British Naturalisation on the basis that you have either spent 5 years in the UK lawfully, or 3 years in the UK as the spouse of a British citizen.
Step 1:Have lived legally in the UK for 5 years – you must not have been away from the UK for more than 450 days during that time, or 90 days during the last year
Step 2:Have held Indefinite Leave to Remain in the UK for at least 1 year at the time you make the application
Step 3: Be 18 years of age or over, pass the Life in the UK test, and Intend to have the UK as your main home.