People will normally be eligible to apply for naturalisation under section 6 of the British Nationality Act 1981.
Do you Qualify:
Naturalisation is not an entitlement and a decision can only be made to grant you
citizenship if you can demonstrate that you satisfy certain legal requirements and the Home Secretary thinks fit to naturalise you.
The requirements for naturalisation as a British citizen differ depending on whether or not you are applying on the basis of marriage or civil partnership with a British citizen.
If you are married to a British Citizen or if you are a civil partner of a British Citizen then section 6 (2) of the British Nationality Act 1981 will apply.
Requirements are:
a) Aged over 18 or over
b) Married or a civil partner of the British Citizen on the date of the application
c) Are of a sound mind
d) Life in the UK
e) English language requirement
f) 3 years residence (lived in the UK before applying)