British Nationality Act 1981
The Home Secretary may if he thinks fit naturalise a person who meets certain requirements which are set out in section 6 of, and Schedule 1 to, the British Nationality Act 1981. These are described below.
1. The person who is applying must meet the requirements that are set out in Part A of this leaflet, unless he or she is married to, or the civil partner of, a British citizen. If the person applying is the husband, wife or civil partner of a British citizen, he or she only needs to meet the requirements that are set out in Part B of this leaflet.
2. The person applying must: a. be aged 18 or over;
b. not be of unsound mind;
c. be of good character;
d. have sufficient knowledge of English, Welsh or Scottish Gaelic (see Note 1);
e. have sufficient knowledge about life in the United Kingdom (see Note 1);
f. intend to have his or her home (or main home if there is more than one) in the United Kingdom. The person applying may, however, live abroad if he or she plans to go into, or continue in Crown service working directly for the Government of the United Kingdom (see Note 2), if he or she plans to work with an international organisation which the United Kingdom is a member of, or work for a company or association established in the United Kingdom; and
g. meet the residential requirements set out in paragraph 3 below (but see also paragraph 4) or the alternative requirement described in paragraph 5.
3. The residential requirements are that: a. the person applying was in the United Kingdom (see Note3) at the beginning of the five-year period that ended on the date the application is received;
b. in that five-year period, he or she was not outside the United Kingdom for more than 450 days (see Note 4);
c. in the last twelve months of that five-year period, he or she was not outside the United Kingdom for more than 90 days;
d. in the last 12 months of that five-year period, his or her stay in the United Kingdom was not subject to any time limit under the immigration laws (see Note 5); and
e. he or she was not, at any time in that five-year period, in the United Kingdom in breach of the immigration laws (see Note 6).
4. Everyone who applies must meet the requirements described in paragraph 2a, c and f. They must also be free from any time restriction under the immigration laws when the application is received and meet the requirement described in paragraph 3a (unless covered by paragraph 5 below). But the Home Secretary may make an exception to the other requirements (including the one in Note 4 about time which does not count) if he thinks that there are special circumstances. If you do not meet the requirements, but you believe that there are special circumstances in your case, you should explain them when you apply.
5. An alternative to the five-year residential requirement is Crown service under the Government of the United Kingdom (see Note 2). There is no fixed period of service because naturalisation will not be granted if you just complete a period of satisfactory service. If someone applies because of Crown service, he or she should, among other things, have held a responsible post overseas, given outstanding service, and have some close connection with the United Kingdom. If someone applies for naturalisation on the basis of Crown service, he or she must be serving outside of the United Kingdom when the application is received.