Foreign nationals may naturalise as Pakistani citizens after residing in the country for at least five years and showing proficiency in at least one vernacular language of Pakistan.

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.

[7] Despite Britain's sovereignty over both types of holdings, domestic law in the United Kingdom treated the princely states as foreign territory.

[20] Pakistan transitionally retained the British sovereign as its head of state in the post-partition period, using its Dominion status as a deterrent against possible Indian incursion.

Provisions in the Pakistan Citizenship Act, 1951 reflect this and provided a pathway for migrants to automatically acquire a status matching the country of their choice post-partition.

[26][27] 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.

[30][27] Britain somewhat relaxed these measures in 1971 for patrials, subjects whose parents or grandparents were born in the United Kingdom,[29] which gave effective preferential treatment to white Commonwealth citizens.

The decision was unpopular among the local populace and triggered revolts organised by those who wanted the state to join Pakistan, leading to the Indo-Pakistani War of 1947–1948.

[38] At the time of partition, Pakistan included East Bengal, a noncontiguous territory separated from the rest of the country by India.

[39] Bihari Muslims, a community of citizens who migrated to East Bengal from the Indian state of Bihar during the partition of India, was particularly affected by Bangladeshi independence.

[40] The vast majority of this minority group were stateless until 2008, when the Bangladesh High Court ruled that Biharis born in the country would be granted citizenship.

Although these refugees were to be repatriated following agreement of the 1988 Geneva Accords, the vast majority have remained in Pakistan due to ongoing instability in Afghanistan.

In the 1999 case Ghulam Sanai v. Assistant Director, National Registration Office, the Peshawar High Court ruled that the provisions for citizenship by birthplace and descent in the 1951 Act should be interpreted together in a correct reading of the law.

[45][46] The Islamabad High Court issued a contradictory judgement in 2018, ruling that a child of Somali refugees had acquired Pakistani citizenship by virtue of birth in Pakistan and that the 1951 Act should be interpreted as written rather than in the method prescribed by the Peshawar court,[47] along with a further ruling in 2022 that any person born in Pakistan was entitled to Pakistani citizenship.

[48] There were 1.7 million undocumented Afghan refugees living in Pakistan without citizenship or residency in November 2023, when the government began a mass deportation initiative to expel all illegal migrants from the country.

[49] Any person born in Pakistan since 13 April 1951 automatically receives Pakistani citizenship by birth except if they are the child of a foreign diplomat or enemy alien.

Individuals born to parents who are citizens by descent only may alternatively acquire citizenship if their births are registered at a Pakistani diplomatic mission.

However, minor children of Pakistani mothers could apply for registration as citizens in a separate process that was subject to discretionary approval of the government.

[56] Naturalised citizens may be involuntarily deprived of the status if they fraudulently acquired it, are sentenced to imprisonment for more than 12 months in any jurisdiction in the world, or they wilfully perform an act that constitutes a breach of loyalty to the state.

Any citizen who continuously resides abroad for more than seven years are also subject to deprivation, unless they are employed by the government while overseas or have submitted a declaration of intent to retain citizenship at a Pakistani diplomatic mission.

[58] Despite this lack of deprivation, Pakistan has concluded a series of bilateral agreements with other countries that explicitly allow dual nationality with the participating states.