Population Registration Act, 1950

The Population Registration Act of 1950 required that each inhabitant of South Africa be classified and registered in accordance with their racial characteristics as part of the system of apartheid. This law worked in tandem with other laws passed as part of the apartheid system. Under the Prohibition of Mixed Marriages Act of 1949, it was illegal for a white person to marry a person of another race. With the enactment of the Immorality Amendment Act of 1950, it also became a crime for a white person and a person of another race to have sexual intercourse.

Social rights, political rights, educational opportunities, and economic status were largely determined by the group to which an individual belonged. There were three basic racial classifications under the law: Black, White and Coloured (mixed). Under the act, as amended, Coloureds and Indians were formally classified into various subgroups, including Cape Coloured, Malay, Griqua, Chinese, Indian, Other Asian and Other Coloured. Indians (that is, South Asians from the former British India, and their descendants) were later added as a separate classification as they were seen as having "no historical right to the country".

In 1910 the Union of South Africa was established with four provinces based on the old colonies of the Cape, Natal and the two Afrikaner republics of the Free State and the Transvaal, with a white parliament. Prior to this Union, each of the four colonies or republics had its own laws on how race was classified when it came to legislation containing race. Most classifications were based on whether one was white or a native, with coloured people linked under the native category. How race was classified, however, differed. In the Transvaal, it was based on appearance and descent, Free State, appearance, descent, general acceptance, repute and living conditions, while in Natal, it offered no criteria expect that it asked whether the native race originated from south of the equator. In Free State, people classified as Indian could not reside there, while Natal and the Transvaal had laws concerning living and working locations and identity documents, while Chinese immigration was banned in the Transvaal after 1906.

With the Union of 1910, its parliament sought to create legislation that applied to the whole country, but legislation enacted that contained segregation-based content, failed to establish a uniform means to define race to the extent that a person could be classified as a different race by different sets of legislation. Essentially, most race-based legislation had either one criterion or all four types of criteria to decide one's race, these being descent, appearance, acceptance and repute, and lastly mode of living. The 1911 Native Labour Regulation Act was one of the first laws that aimed to collect tax from natives (black South Africans), but was soon challenged by the courts as it had failed to exclude coloureds.

The Department of Native Affairs that applied the various forms of legislation did so with no clearly defined way of establishing a person's race, and so applied various sources and personal judgements. It attempted in 1926, via the Secretary for Native Affairs, to clarify who was native versus who was coloured and again in 1946, defining that a native would be determined by what was in each piece of individual legislation. So race classification could be established by the Native Affairs department via a case by case basis based on sources such as appearance, associating with other natives in their environment, language spoken or natural language used, where district of domicile, whether they lived in a location, paid native tax, and if married, was the spouse native and was lobolo paid. Other tests claimed to have been used included the hair test, eyelid test and intimate medical examinations such as genital pigmentation.

Basing race on descent was a troubling idea for white politicians in charge of legislation, best left undiscussed, as there were some in the white population whose ancestors had in the past married others who weren't white.

In 1921, the idea of classifying race in South Africa was proposed by Mine Minister Patrick Duncan. The idea, which proceed no further than that, was to create a national population register and classify the population by race. The idea arose again in 1935 when a parliamentary select committee discussed it, but was soon dismissed as impracticable and costly.

In November 1948, the first inkling of the future legislation which would be known as the Population Registration Act, was announced by prime minister D. F. Malan at a Transvaal National Party Congress. He announced all South African races would be registered and issued with an identity card, and would supersede all current forms of identification. He made it clear that it would assist in the application of apartheid law, in particular, to identify which areas races could live in and who they could marry. Other areas it could be used, he said, were in identifying non-South Africans (aliens) and assisting in voter registration. One thing he suggested was that anyone with one-sixth black blood, a person's grandparents, would be classified as coloured, something that never made it into the future legislation.