One way to acquire Portuguese Nationality is through non-marital partnership for more than three years, as foreseen by article 3 of the Portuguese Nationality Law (Law n. 37/81, of October 3rd).
Unlike marriage, for the purpose of obtaining Portuguese Nationality, in a non-marital partnership it will be necessary to propose a lawsuit for recognition of the non-marital situation.
A non-marital partnership is the legal situation of two people that, regardless of gender, have been living under the same conditions as spouses for more than two years, and benefits from the protection provided by Law no. 7/2001, of May 11 (with several modifications).
The non-marital partnership is proved by any legally admissible means and the respective lawsuit for recognition of this situation is brought against the State, represented for this purpose by the Public Ministry.
After the respective judicial decision has been handed down and has become final, the applicant can then submit the request for nationality with this and the other documents necessary for the purpose.