British nationality law as it pertains to Hong Kong has changed over time since it became a British colony in 1842. Hongkongers were given various nationality statuses, such as British subjects, Citizen of the United Kingdom and Colonies, British Dependent Territories Citizen and British Nationals (Overseas).

Early colonial era English common law has the rationale of natural-born citizenship, following the principle of jus soli, in the theory that people born within the dominion of The Crown, which included self-governing dominions and Crown colonies, would have a "natural allegiance" to the Crown as a "debt of gratitude" to the Crown for protecting them through infancy. As the dominion of the British Empire expanded, British subjects included not only persons within the United Kingdom but also those throughout the rest of the British Empire.

By this definition, anyone born in Hong Kong after it became a British colony in 1842 was a British subject. The Naturalisation of Aliens Act 1847 expanded what had been covered in the Naturalisation Act 1844, which applied only to people within the United Kingdom, to all its dominions and colonies. The Act made provisions for naturalisation as well as allowing for acquisition of British subject status by marriage between a foreign woman and a man with British subject status.

British Nationality and Status of Aliens Act 1914

The British Nationality and Status of Aliens Act 1914 (now renamed as "Status of Aliens Act 1914") came into force on 1 January 1915, codifying for the first time the law relating to British nationality. No major change was introduced but it set into law how people associated with Hong Kong – as part of "His Majesty's dominions" – would acquire British subject status.

British Nationality Act 1948

The Commonwealth of Nations' heads of government decided in 1948 to embark on a major change in the law of nationality throughout the Commonwealth. It was decided at the conference that the United Kingdom and the self-governing dominions would each adopt separate national citizenship, but retain the common imperial status of British subject. The British Nationality Act 1948 provided for a new status of Citizen of the United Kingdom and Colonies (CUKC), consisting of British subjects who had a close relationship (either through birth or descent) with the United Kingdom and its remaining colonies. The Act also provided that British subjects could be known by the alternative title Commonwealth citizen.

The Act came into force on 1 January 1949 and stipulated that anyone born in "United Kingdom or a colony" on or after that date was a CUKC. Those who were British subjects on 31 December 1948 were entitled to acquire CUKC status by declaration. The deadline for this was originally 31 December 1949, but the deadline was extended to 31 December 1962 by the British Nationality Act 1958.

British Nationality Acts were passed in 1958, 1964 and 1965, which mainly fine-tuned special provisions about CUKC status acquisition.

Commonwealth Immigrants Acts Until 1962, all Commonwealth citizens could enter and stay in the United Kingdom without any restriction. Anticipating immigration waves from former and current colonies in Africa and Asia with the decolonisation of the 1960s, the United Kingdom passed the Commonwealth Immigrants Act 1962 to tighten immigration control for Commonwealth nationals into the United Kingdom, and the Commonwealth Immigrants Act 1968 modified the wording of the 1962 act to apply to certain colonial CUKCs.

The Commonwealth Immigrants Act 1968 made a number of changes to the Commonwealth Immigrants Act 1962, beginning with amending the definition of to whom the Act applied. By comparison:

Commonwealth Immigrants Act 1962:

Commonwealth Immigrants Act 1968:

As such, CUKCs connected with Hong Kong were subject to immigration control after 1968.

Finally, under the Immigration Act 1971, the concept of patriality or right of abode was created. CUKCs and other Commonwealth citizens had the right of abode in the UK only if they, their husband (if female), their parents or their grandparents were connected with the United Kingdom. This placed the UK in the rare position of denying some of its nationals entry into their country of nationality. However, the concept of patriality was only a temporary solution to halt a sudden wave of migration. The British government later reformed the law, resulting in the British Nationality Act 1981.

These acts shaped an increasingly restrictive immigration policy into the UK for Hong Kong residents even before the Sino-British Joint Declaration of 1984.

British Nationality Act 1981 and British Dependent Territories Citizenship

The British Nationality Act 1981 created new categories of British nationality and renamed British colonial territories. After implementation, all British Crown colonies became British Dependent Territories. The Act abolished the status of CUKC, and replaced it with three new categories of nationality on 1 January 1983: British Citizen (for residents of the UK and the Crown dependencies) British Dependent Territories Citizen (BDTC) (for the Crown colonies), and British Overseas Citizen (BOC) (a class of non-inheritable nationality for those who are unable to become a British Citizen, a BDTC or a national of another country)

The law stated that those who have CUKC status by connection with Hong Kong and those born in Hong Kong on or after 1983 to a parent settled in Hong Kong are BDTCs. The law also stated that British Citizens or BDTCs by descent could not automatically pass on British nationality to a child born outside the United Kingdom or the dependent territories concerned unless a parent acquired citizenship otherwise than by descent.

After the Sino-British Joint Declaration

Negotiation concerning the future of Hong Kong started in the late 1970s between Britain and China. With the signing of the Sino-British Joint Declaration on 19 December 1984, the future of Hong Kong was set, with China to assume sovereignty of the entire territory of Hong Kong on 1 July 1997.

At that time, there were some 3.5 million residents of Hong Kong with BDTC status by virtue of their connection with Hong Kong. Another 2 million were believed to have been eligible to apply to become BDTCs. After the handover, they would have lost this status and became solely Chinese nationals. At the time, Hong Kong was the largest of the remaining British dependent territories with over 5 million inhabitants.

Creation of the British National (Overseas) status

The Hong Kong Act 1985 created an additional category of British nationality known as British National (Overseas) or BN(O). This new category was available only to Hong Kong BDTCs, and any Hong Kong BDTC who wished to do so would be able to acquire the status of BN(O). The status was non-transferable and available only by application, and the deadline to apply was 30 June 1997.

British Overseas Citizen status for those who are 'otherwise stateless' Any Hong Kong BDTCs who failed to register as a BN(O) by 1 July 1997 and would thereby be rendered stateless (generally because they were a non-ethnic Chinese and therefore could not automatically acquire Chinese nationality), automatically became a British Overseas Citizen under the Hong Kong (British Nationality) Order 1986.

British Nationality Selection Scheme

After the Tiananmen Square massacre in 1989, many people in Hong Kong began to fear for their future post-1997. Emigration was rampant and a brain-drain was beginning to affect the economy of Hong Kong. To stem the drain, people urged the British government to grant full British citizenship to all Hong Kong BDTCs – but this request was never accepted. However, the British did agree to creating the British Nationality Selection Scheme, which granted to a select 50,000 people and their families the ability to obtain full British citizenship without having to fulfil the ordinary requirements, under the British Nationality (Hong Kong) Act 1990. Under the Act, the Home Secretary was required to register any person recommended by the Governor of Hong Kong (as well as the applicant's spouse and minor children) as a British Citizen. Any person who was registered under the act automatically ceased to be a BDTC upon registration as a British Citizen. No person could be registered under the act after 30 June 1997.

Hong Kong (War Wives and Widows) Act 1996 Women who had received assurance from the Secretary of State that they would be eligible for settlement in the United Kingdom on the basis of their husband's war service in the defence of Hong Kong may be registered as British Citizens if they were resident in Hong Kong and had not remarried. There is no requirement for the woman to hold (or have held) any form of British nationality. Women registered as British Citizens under this act acquire British citizenship "otherwise than by descent" and thus also their children would be British Citizens.

British Nationality (Hong Kong) Act 1997 Another special group of solely Hong Kong British nationals were the non-Chinese ethnic minorities of Hong Kong. They are primarily immigrants or children of immigrants from Nepal, India and Pakistan. After the handover to China, they would not be accepted as inherently being citizens of the People's Republic. They would be left effectively stateless – they would have British nationality and permanent residency and right of abode in Hong Kong, but no right of abode in the UK, nor a right to claim Chinese nationality.

The ethnic minorities petitioned to be granted full British citizenship,A Pasage to Nowhere (Prism Nov 1995) accessed 1 Aug 2010 and were backed by several politicians. Jack Straw, then the Shadow Home Secretary, said in a letter to the then Home Secretary Michael Howard dated 30 January 1997 that "common sense and common humanity demand that we give these people full British citizenship. The limbo in which they will find themselves in July arises directly from the agreements which Britain made with China". He further stated that a claim that BN(O) status amounted to British nationality "as pure sophistry".The Economist also said that "the failure to offer citizenship to most of Hong Kong's residents was shameful", and "it was the height of cynicism to hand 6 million people over to a regime of proven brutality without allowing them any means to move elsewhere." The article also stated that the real reason that the new Labour government still refused to give full British citizenship to other BDTCs was because if the UK waited until Hong Kong had been disposed of it "would be seen as highly cynical", as The Baroness Symons of Vernham Dean, a Foreign Office minister, conceded. ("Britain's colonial obligations", 3 July 1997, The Economist) The subsequently enacted British Nationality (Hong Kong) Act 1997 gives them an entitlement to acquire full British citizenship by making an application to register for that status after 1 July 1997.

Nationality, Immigration and Asylum Act 2002 In light of the passing of the British Overseas Territories Act 2002, which made provision to substitute the wording of "British Dependent Territories" with "British Overseas Territories" in the British Nationality Act 1981 among other new provisions, further clarification was made even though this act did not even apply to Hong Kong. Section 14 of the subsequent Nationality, Immigration and Asylum Act 2002 stated specifically that a person may not be registered as a British Overseas Territories Citizen (BOTC) by virtue of a connection with Hong Kong.

Borders, Citizenship and Immigration Act 2009