One of three forms of citizenship introduced by the British Nationality Act 1981, which replaced citizenship of the UK and Colonies. The others were British Dependent Territories citizenship (now British Overseas Territories citizenship) and British Overseas citizenship.
On the date on which it came into force (1 January 1983), the Act conferred British citizenship automatically on every existing citizen of the UK and Colonies who was entitled to the right of abode in the UK under the Immigration Act 1971. As from that date, there have been four principal ways of acquiring the citizenship – by birth, by descent, by registration, and by naturalization. A person acquires it by birth if he is born in the UK and his father or mother is either a British citizen or settled in the UK (i.e. resident there, and not restricted by the immigration laws as to length of stay). If born outside the UK, he acquires it by descent if one of his parents has British citizenship (but not, normally, if that citizenship was itself acquired by descent). The British Nationality (Falkland Islands) Act 1983 made special provision to confer British citizenship on those people with connections with the Falkland Islands. The British Nationality (Hong Kong) Act 1997 gave additional rights to certain people from Hong Kong to acquire British citizenship. Finally, the British Overseas Territories Act 2002 extended full British citizenship to nearly all British Overseas Territories citizens, most of whom now hold both forms of citizenship. Registration may be applied for by a minor, but adults are eligible only if they have particular links with the UK. In some cases (e.g. British Overseas Territories citizens, British Overseas citizens, British protected persons, and British subjects with certain residential qualifications), it is a right; in others, it is at the discretion of the Secretary of State. Any adult may apply for naturalization but there are residential and other requirements (e.g. proof of good character), and its grant is always discretionary. The Nationality, Immigration and Asylum Act 2002 imposes a condition that applicants should demonstrate a knowledge of British life and culture.
A registered or naturalized citizen may be deprived of his citizenship if he obtained it improperly, behaves disloyally, or is sentenced during the first five years to imprisonment exceeding one year. The Immigration, Asylum and Nationality Act 2006 also contains several provisions empowering the Home Secretary to deprive a person of British citizenship (or right of abode) if it is considered that such deprivation is “conducive to the public good” (s 56). For example, the Australian Guantanamo Bay inmate David Matthew Hicks applied for British citizenship based on his maternal heritage (as allowed by the 2002 Act). Hicks was granted citizenship on 5 July 2006, but stripped of it several hours later under section 56 of the 2006 Act.