All persons born in India between 26 January 1950 and 1 July 1987 automatically received citizenship by birth regardless of the nationalities of their parents.

Operations became more lucrative as the Mughal Empire entered into decline in the 18th century, giving the company opportunity to gain further advantages by intervening in regional politics.

The vast financial resources of the firm and its superior military enabled it to defeat rival European trade companies and become the dominant power in India.

[9] Although Britain held comprehensive jurisdiction in both types of holdings, domestic law treated the princely states as foreign territory.

[23] This ideal was directly contradicted by a series of immigration restrictions in other colonies and Dominions that were created to exclude non-white migrants, including Indian British subjects, from entering their borders.

[24] Australia, Canada, New Zealand, and South Africa all enacted legislation severely restricting Indian immigration in some form by the early 20th century.

[27] While the imperial government had recognised these claims as legitimate prior to the First World War, it was nervous at the prospect of these movements becoming revolutionary in nature and decided to forcefully suppress local unrest rather than politically address Indian concerns.

The Act abandoned the common nationality used across the Empire and redefined British subject to mean any citizen of a Commonwealth country.

[34] The citizenship provisions of the Constitution of India came into force on 26 November 1949,[35] in advance of the document's full effective date and the country's conversion into a republic on 26 January 1950.

While the British Indian government had encouraged Nepalese to settle in northeastern India to facilitate the growth of tea plantations in that area, high levels of migration between the two countries continued to occur due to cultural and religious similarities.

[42][43] Non-white immigration into the UK was systemically discouraged, but strong economic conditions in Britain following the Second World War attracted an unprecedented wave of colonial migration.

[46][43] Britain somewhat relaxed these measures in 1971 for patrials, subjects whose parents or grandparents were born in the United Kingdom,[45] which gave effective preferential treatment to white Commonwealth citizens.

French-administered Chandernagore held a referendum in 1949 resulting in the city's merger with West Bengal,[53] while the rest of French India was relinquished by 1954.

[55] Although most residents of these territories were given a choice between acquiring Indian citizenship and retaining their previous nationalities, those from Dadra and Nagar Haveli were not.

[56] In Goa, Daman and Diu, residents automatically became Indian citizens on 20 December 1961 unless they had made a written declaration before this date stating their intention to retain their existing nationality.

[57] Portugal did not recognise the annexation of its former Indian territories;[58] persons born in applicable areas before 3 June 1975 were recognized as Portuguese citizens.

[60] Although Britain (and later India) had control over its foreign affairs, Sikkim was never considered a princely state and always held full autonomy over domestic matters.

[62] After the dissolution of Sikkim's monarchy and its accession to India in 1975, any person registered as a Sikkimese subject before 26 April 1975 became an Indian citizen.

[65] This process of acquisition left certain groups of people living in Sikkim stateless including long-term residents without property, Sikkimese women who married non-Sikkimese, and individuals who had otherwise qualified for subject status but failed to complete registration before 1975.

Successive governments since the 1980s have gradually increased the difficulty of acquiring Indian citizenship in response to changing patterns of immigration from neighbouring countries.

British authorities encouraged workers from outside the region to resettle there to provide a continual source of labour for railway construction, agricultural development, and resource mining.

[71] The highest levels of migration occurred in the decade following the 1971 Bangladesh Liberation War;[72] an estimated 1.8 million people settled in the state in the 1970s, compared to 221,000 in the 1950s and 424,000 in the 1960s.

[75] Protest organisers and government officials ultimately agreed on the Assam Accord in 1985, which resulted in the addition of Section 6A to the Citizenship Act that same year.

[76] Under this change, any person who had been living in Assam prior to 1966 was an Indian citizen; those who settled there between 1966 and 1971 were removed from electoral rolls and subject to a 10-year waiting period before becoming eligible to register for citizenship.

[56] Restrictions were selectively relaxed in 2019 for migrants from neighbouring countries belonging to certain religious groups who illegally entered India before 2015; persons from Afghanistan, Bangladesh, and Pakistan who are Hindus, Sikhs, Buddhists, Jains, Parsis, or Christians are not counted as illegal migrants for nationality purposes[79] and are eligible for a reduced six-year residence requirement for naturalisation.

[82] 1.9 million people failed to provide sufficient documentation and were not listed on the register, leaving them stateless and subject to deportation.

[83] All persons born in India between 26 January 1950 and 1 July 1987 automatically received citizenship by birth regardless of the nationalities of their parents.

From 1 July 1987 until 3 December 2004, children born in the country received Indian citizenship by birth if at least one parent was a citizen.

The birth of eligible persons must be registered at an Indian diplomatic mission within a certain time frame for citizenship to be granted.

[99] All persons who (or whose parents or grandparents) have ever been citizens of Pakistan or Bangladesh are permanently ineligible for overseas citizenship.