By birth

Any child born within the borders of the United Republic of Tanzania, on or after Union Day, 26 April 1964, is granted Tanzanian nationality, except for children of a father who has diplomatic immunity, or parents who were enemy aliens and the territory was under enemy occupation.^[12][8] In practice, to acquire nationality at birth the parents must also be Tanzanian, or the parents must be unknown, as in the case of an abandoned child.^[8][13] A person born outside Tanzania enjoys a right to Tanzanian nationality from birth provided that at least one parent is a Tanzanian by birth or naturalization.^[14] However, some Tanzanians born abroad may not pass their nationality on to their children, meaning that if a child's father acquired nationality by birth abroad, the child can only acquire nationality through naturalisation. The same rule does not apply to children born abroad to a mother who acquired nationality by birth abroad.^[8]

By naturalisation

Any foreign national with no ancestry or birth ties with Tanzania may apply for naturalisation. In order for a foreign national to become Tanzanian they must have resided in the territory for a sufficient period of time to confirm they understand either Swahili or the English language and the customs and traditions of the society.^[15] General provisions are that applicants must be of the age of majority and have legal capacity; have good character; have the ability to contribute to the growth of the social and cultural advancement of the country; and intend to permanently reside in the territory.^[15][10] Residency for the full year preceding an application is required, as well as evidence that over the preceding ten-year period, the applicant has cumulatively lived in Tanzania for at least seven years.^[10] Following the lodging of the application and paying fees to the Ward Executive Secretary or Zanzibari Sheha, local village administrators, the application is sent to the District Immigration Office.^[10][16] The applicant must publish a notice of intention to naturalise in two consecutive issues of the registered newspapers. After the application has been scrutinised by various officials, a final recommendation is made to the Minister of Home Affairs.^[10] If the application is successful, applicants must renounce foreign nationality and take an oath of allegiance.^[15][10] Besides foreigners meeting the criteria,^[15] other persons who may be naturalized include:

• Children born abroad to a father who acquired nationality by descent because of his birth abroad may naturalise without meeting other requirements;^[15]
• Minor children may be naturalised simultaneously with their parents;^[15]
• Adoptees may apply for naturalisation upon completion of a legal adoption;^[17]
• Any minor may be naturalised at the discretion of the Minister of Home Affairs if special circumstances exist;^[18]
• The wife of a Tanzanian husband may upon request become naturalised, if she is willing to renounce other nationality and take an oath of allegiance, unless she previously was denaturalised or renounced Tanzanian nationality; or^[19]
• Wives who previously lost Tanzanian nationality must obtain approval from the Minister of Home Affairs.^[18]

African and outsider contact (1498–1884)

In 1498, Portuguese navigator Vasco da Gama reached the African Great Lakes coast, and landed at Quelimane, before proceeding north to encounter hostile Arab sultanates, which were aligned with the Kilwa Sultanate.^[39] In 1500, Pedro Álvares Cabral landed on Kilwa Island and two years later, da Gama returned to the island and claimed it for Portugal.^[38] In 1503 or 1504, Ruy Lourenço Marques Ravasco (also known as Rui Lourenço Ravasco) landed on Unguja and engaged in a battle with the local inhabitants. Defeating the local ruler, Portugal laid claim to Zanzibar.^[40][41] In 1505, Francisco de Almeida seized the island and began construction of a trading fort at São Thiago.^[38][41] In 1652, Omani tribesmen from Muscat attacked the Portuguese settlements on Pemba Island and Zanzibar. They continued attacks along the coast to the Ruvuma River in the 1660s and by 1698 had captured Fort Jesus, on Mombasa Island.^[38] By the late eighteenth century the Omani Empire had established control over Kilwa and the coastal region.^[42]

Few foreign explorers or merchants attempted to travel into the interior until the eighteenth century. By 1800, Nyamwezi people had begun participating in trade with the coast.^[37] Between 1811 and 1820, the Sultan of Zanzibar sent caravans inland in search of ivory and slaves.^[37][42] By 1830, Arab-Swahili merchants had networks running from the coastal towns to trading posts in Tabora and as far west as Ujiji and from Lake Tanganyika in the south to the Kingdom of Buganda in the north.^[37] Increased activity from Europeans and Americans began in the early nineteenth century. Britain signed the Moresby Treaty with the Sultan of Zanzibar, outlawing the sale of slaves to Christian merchants. Further treaties were conclude in 1833 with the United States, 1844 with France, and 1858 with Germany to allow trade in the region.^[43] By the end of the nineteenth century, Germany and Britain were competing for control of the area.^[44]

Tanganyika

Zanzibar Protectorate (1890–1963)

The British established a protectorate over the islands of Zanzibar and Pemba on 4 November 1890, acquiring extraterritorial jurisdiction over British subjects. To gain Germany's acceptance for the creation of the protectorate, Britain ceded Heligoland to Germany that year.^[62] British Nationality Acts did not extend beyond the bounds of the United Kingdom of Great Britain and Ireland, meaning that under Britain's rules of conquest, laws in place at the time of acquisition remained in place until changed.^[63][64] Because the Sultan of Zanzibar had an existing government, Zanzibar was treated as a Protected State under British laws, rather than a protectorate, for which Britain would have administered internal and external government functions.^[65]

Pre-union (1961–1963)

On 9 December 1961, Tanganyika gained its independence. Under the Independence Constitution, Tanganyikan nationality was conferred on that date upon anyone who had previously been born in Tanganyika or any person who had previously been a CUKC or BPP of Tanganyika, if one of its parents had also been born in Tanganyika. Persons born outside of the territory were conferred nationality if their father became, or would have become except for his death, Tanganyikan by birth.^[103][104] Those who acquired Tanganyikan status ceased to be British; however provisions were made for persons, such as the large Indian popuplation who might have been born in the territory but whose father was not or wives of persons who did not acquire Tanganyikan nationality, to retain their status as CUKCs or BPPs if they had been born, registered, or naturalised in a place which remained part of the British realm or a state protected by Britain.^[105] Those born after independence acquired nationality by birth in Tanganyika, as long as neither parent was an enemy alien or had diplomatic immunity or by birth abroad through a father who had been born in Tanganyika, as long as the father had not been a CUKC or BPP.^[106] For a two-year period after independence persons, or their guardians for minor children, who had been born in Tanganyika to foreigners prior to independence; wives of Tanganyikans whose husbands became Tanganyikan at independence or would have become nationals except for their death, wives whose husbands registered in the transitional period or divorcées of such a person; and persons who had previously been naturalised or registered as CUKCs in Tanganyika were allowed to register as nationals.^{[107][Notes 2]} After independence, wives could be naturalised upon marriage to a Tanganyikan, but naturalisation rules were to be provided in the nationality law. Dual nationality was permissible only to minors born with multiple nationalities. Upon reaching majority, one nationality was required to renounced.^[107]

On the one-year anniversary of independence Tanganyika became a republic within the Commonwealth and adopted verbatim the rules contained in the Independence Constitution as the Citizenship Act 1961.^[109] In 1962, Tanganyika amended its Citizenship Act (Law No. 69) to allow "persons of African descent from Angola, the Cape Verde Islands, the Comorian Islands, French Somaliland, Mozambique, Portuguese Guinea, the San Tome and Principe Islands, Spanish West Africa, and the Republic of South Africa" to acquire Tanganyikan nationality after a five-year residency if they were proficient in English or Swahili. It was also amended in 1963 (Law No. 19) to allow any woman married after independence to be registered as a national upon marriage to a Tanganyikan.^[108] On 10 December 1963, Zanzibar acquired independence and persons who had been BPPs in the protectorate ceased to hold that status. Anyone who had been a subject prior to independence was conferred Zanzibari nationality at independence, thus even CUKCs who had been born in Zanzibar were no longer British nationals. The only exceptions were persons (and their wives) who were born, registered, or naturalised in a place that remained within the British realm after independence.^[66] After independence, nationality was acquired by persons born in the Sultan's dominions to Zanzibari parents, as long as the father did not have diplomatic immunity or was classed as an enemy alien. Persons born outside the Sultan's territories could acquire nationality through a Zanzibari father. Wives of Zanzibari husbands and parents or guardians of minor children who were not Zanzibari could apply on behalf of the child for nationality through registration. Nationality provisions did not change from the 1958 Decree.^[110]

On 12 January 1964, the Zanzibar Revolution broke out and the sultan was deposed.^[66] The Afro-Shirazi Party took over the government, established a one-party state, and repealed the independence constitution. Under the Existing Laws Decree (No. 1-1964) the nationality statutes of 1911, as amended in 1958 became law again, meaning that certain Asian nationals who had become nationals at independence were deprived of their nationality and became stateless for approximately four months.^[111][112]

Post-union (1964–present)

On 26 April 1964, the United Republic of Tanganyika and Zanzibar was formed, which was renamed as the United Republic of Tanzania on 29 October 1964.^[111][113] Effective with the date of union, Tanganyika's Citizenship Act 1961 was modified (Tanganyika Extension and Amendment Decree, Law No. 5, 1964) to recognise nationals of the United Republic as those born prior to the union in either state as nationals of the new republic and those born after the union as nationals if they were born in any part of the territory.^[113] In 1980, refugees fleeing from violence in Burundi and Rwanda were granted the right to apply for Tanzanian nationality as a group. Typical application processes and fees were waved and upon completion of the process, former refugee camps transitioned to Tanzanian villages. The process of receiving documents and nationality certificates was slow and many former refugees had still not received them after decades.^[114] Burundi and Rwandan refugees migrated again in excellerated numbers from the mid-1990s, causing strain to Tanzania's ability to integrate the population and causing security concerns. In reaction, refugees were both expelled by the government and the army forceably removed refugees and closed the border with Rwanda in 1996.^[115] Though political developments in the country caused the constitution to be rewritten and amended, no changes were made to the nationality requirements or laws until 1995.^[116]

In 1995, the Citizenship Act 1961 was repealed though nationality gained under the former Act continues to be recognized.^[117] Under the terms of the Tanzania Citizenship Act 1995 anyone who was a national of Tanzania on or before 26 April 1964 and was born in either Tanganyika and Zanzibar, or was born abroad to parents who were nationals before the union, or had been previously naturalised or registered was conferred nationality.^[118] Those born after the union, acquire nationality by birth in the territory to parents who are Tanzanian, unless the father had diplomatic immunity or either parent was an enemy alien, or by descent through a parent who is a Tanzanian national.^[119] The Act eliminated nationality by registration, consolidating former categories with naturalisation.^[117] Persons wishing to naturalise must renounce other nationality, speak one of the languages of the country, be of good character and able to contribute to the country's development, and have lived in the country for a minimum of eight years.^[10] Wives of Tanzanians may naturalize after proving that they are legally married, that their husband is Tanzanian, hold a valid passport, and have immigrated. Neither widows nor divorcées are entitled to naturalise. Dual nationality is prohibited except for minor children who acquired multiple nationality from birth. At majority only one nationality is allowed.^[18]

In 1997, the army again was ordered to expel refugees residing outside of designated camps. In 1998, a Refugee Act was passed requiring refugees to live in designated areas. This policy was updated as the National Refugee Policy in 2003 with plans to extend nationality to certain refugees. In June 2003, the Tanzanian government offered Somali refugees who had fled the civil war in their country the opportunity to acquire Tanzanian nationality. It extended a similar offer in 2007 to Burundi nationals and their descendants who had left their homeland since 1972.^[120] In 2011, a Constitutional Review Commission was formed which carried out public consultations before preparing a Draft Constitution in 2013. The draft proposals would recognise nationality based on birth to a Tanzanian and would replace the naturalisation scheme by reintroducing registration. Under its provisions either spouse would be able to register as Tanzanian by marriage and would be unaffected by a termination of the marriage if registered. It would make provisions for foundlings who are under age seven to acquire nationality^[121] and does not address dual nationality or deprivation of nationality, but does contain a provision that laws concerning acquisition will be made by the national parliament.^[122] A referendum to adopt the proposed draft in 2015 was postponed and the process has stalled.^[123] In September 2013, the refugee program was suspended while the naturalisation processes were incomplete. Approximately 35,000 refugees were forcibly expelled, before the policy resumed processing naturalisation petitions for Burundi refugees in 2014.^[120]