British nationality law

The primary legislation governing nationality in the United Kingdom is the British Nationality Act 1981, which came into force on 1 January 1983. Its provisions apply to the British Islands (comprising the United Kingdom (England, Wales, Scotland and Northern Ireland), and the Crown dependencies, of Jersey, Guernsey and the Isle of Man) and the 14 British Overseas Territories.

The six classes of British nationality provide differing levels of civil and political rights, reflecting the United Kingdom's historical legacy as a colonial power. The primary form is British citizenship, which is linked to the British Islands and confers full rights. Those connected with a current overseas territory are classified as British Overseas Territories citizens (BOTCs), and since 2002, nearly all BOTCs, except those associated solely with Akrotiri and Dhekelia, have also held British citizenship. Other residual forms of British nationality generally linked to former colonies and now largely closed to new acquisition include the statuses of British Overseas citizen, British subject, British National (Overseas) and British protected person. These categories do not confer automatic right of abode in the United Kingdom and offer limited entitlements.

All individuals born in the British Islands prior to 1 January 1983 were automatically granted British citizenship by birth (jus soli), irrespective of their parents' nationalities. To become a British Citizen under the 1981 Act, it was necessary to hold Citizenship of the UK and Colonies as well as Right of abode in the United Kingdom on 31 December 1982, without which a person would either hold British Overseas Territory citizenship, or British Overseas citizenship.

Since that date, birthright citizenship in those territories has been limited to children with at least one parent who is either a British citizen or holds settled status in the United Kingdom (jus sanguinis). Foreign nationals may apply to naturalise as British citizens after fulfilling a minimum residence requirement, typically five years, and obtaining settled status.

The United Kingdom was formerly a member of the European Union (EU), and during its membership, British citizens were also EU citizens. This conferred automatic and permanent rights to live and work in any EU or European Free Trade Association (EFTA) country, along with the right to vote in elections to the European Parliament. Although the United Kingdom left the EU in 2020 following Brexit, British citizens retain permanent rights to live and work in the Republic of Ireland through the Common Travel Area arrangement.

The distinction between the meaning of the terms citizenship and nationality is not always clear in the English language and differs by country. Generally, nationality refers to a person's legal belonging to a sovereign state and is the common term used in international treaties when addressing members of a country, while citizenship usually means the set of rights and duties a person has in that nation. This distinction is clearly defined in many non-English speaking countries but not in the Anglosphere.

Historically, an individual associated with Britain was neither a national nor a citizen, but a British subject. British citizenship was not created until passage of the British Nationality Act 1981. This Act defined six types of nationality dependent on a person's connections with the United Kingdom, overseas territories, or former colonies.

British citizens hold their status because of a close connection with the British Islands, usually through their own (or parents' or grandparents') birth, adoption, naturalisation, or registration as citizens of the UK. This was defined as right of abode by the Immigration Act 1971.