According to Article 12, item I, of the Federal Constitution, considering the wording employed by Constitutional Amendment No. 54/2007, those born in the Federative Republic of Brazil, even if of foreign parents, provided that they are not in the service of their country, are Brazilian citizens. This also applies to those born abroad, of a Brazilian father or a Brazilian mother, provided that either one of them is in the service of the Federative Republic of Brazil. Those born abroad of a Brazilian father or a Brazilian mother are also entitled to Brazilian citizenship provided that they are registered at a Brazilian office with jurisdiction, or come to reside in the Federative Republic of Brazil, and at any time after reaching the age of majority, choose Brazilian nationality.
The Federal Constitution foresees the possibility of a Brazilian having double or multiple nationalities/citizenships in two scenarios. When there is a recognition of original citizenship by foreign law, Brazil allows dual citizenship. In this case, the individual must be a citizen of a foreign country by merit of birth or descent, rather than naturalisation, to be allowed dual citizenship.
The second instance whereby Brazil allows dual citizenship is when citizenship is imposed by foreign regulations by means of a naturalisation process on a Brazilian resident in a foreign state, as a condition for permanence in their territory or for the exercising of civil rights.
As such, the Brazilian legal system admits that Brazilians may have double or multiple citizenships only if the other nationality/nationalities are derived from the individual’s birth in foreign territory, are of foreign ancestry or naturalisation by imposition of the foreign legislation. Naturalised Brazilians, however, are allowed to keep their foreign nationality. Thus, in accordance with article 12, paragraph 4, item II of the Federal Constitution of 1988, combined with articles 249 and 250 of Decree No. 9.199/2017, any Brazilian who voluntarily adopts another nationality that is in disagreement with the foreseen exceptions provided in the constitutional text, may be subject to an administrative proceeding for the loss of Brazilian nationality.