Portuguese nationality by marriage: what the law says

A foreign national married for more than three years to a Portuguese citizen may acquire Portuguese nationality by declaration made during the marriage, pursuant to art. 3(1) of the Lei da Nacionalidade (Portuguese Nationality Law, Lei n.º 37/81) ^[1]. The application is handled by the Instituto dos Registos e do Notariado (IRN, the Portuguese Institute of Registries and Notaries) and depends on proof of the marriage and other legal requirements.

Who can apply for nationality by marriage?

A foreign national married for more than three years to a Portuguese citizen may declare the acquisition of Portuguese nationality (art. 3(1)) ^[1]. The declaration must be made during the marriage — that is, the marriage must be valid and subsisting at the time of the declaration ^[1].

The acquisition of nationality by marriage also depends on the non-occurrence of any of the situations set out in art. 6(1)(f) to (h) (art. 3(4)) ^[1]. Those subparagraphs concern conviction for serious crimes with an effective prison sentence of more than 3 years, danger or threat to national security, and restrictive measures by the UN or the European Union ^[1].

What is the minimum period of marriage?

The Lei da Nacionalidade requires the marriage to have lasted more than three years (art. 3(1)) ^[1]. The period runs from the date of the marriage, and the declaration must be made during the marriage ^[1].

The law further provides that, where the marriage has lasted more than six years or where the couple have common children holding Portuguese nationality, there is no opposition to the acquisition of nationality (except on the grounds set out in art. 6(1)(f) to (h)), pursuant to art. 9(2) ^[1].

Does annulment of the marriage affect the acquired nationality?

The declaration of nullity or annulment of the marriage does not prejudice the nationality acquired by the spouse who entered into the marriage in good faith (art. 3(2)) ^[1].

Why does documentary evidence matter?

Acquiring nationality by marriage requires the applicant to demonstrate, with documents, the marital bond and the identity of the parties. Where the marriage was celebrated outside Portugal, foreign documents require additional steps to be recognised in the Portuguese legal system — which may include authentication and, depending on the language, translation.

The Regulamento da Nacionalidade (Nationality Regulation) sets out the documents required with the declaration for marriage (art. 14(3)) ^[2] and provides, in certain cases, for the waiver of documents by the applicant (art. 37) ^[2]. Identifying what is required, obtaining it and organising it is part of the support the firm provides in each application.

To understand what applies to your case, tell us about your situation through the contact form. Conecta Fronteiras assesses whether the documentation you have covers what the application requires.

What about de facto unions?

The law provides that a foreign national who, at the date of the declaration, has lived in a de facto union for more than three years with a Portuguese citizen may acquire Portuguese nationality, after the court has issued a judicial decision recognising the de facto union (art. 3(3)) ^[1].

In the case of a de facto union, the Regulation (art. 14(4)) sets out the documents required with the declaration, including evidence of the judicial recognition and the continuation of the relationship ^[2]. Identifying and organising the required documentation is part of the support the firm provides.

The acquisition through a de facto union likewise depends on the non-occurrence of the situations set out in art. 6(1)(f) to (h) (art. 3(4)) ^[1].

How is the application made?

The justiça.gov.pt portal confirms that "Casado/a há mais de três anos com nacional português" (married for more than three years to a Portuguese national) is listed among the grounds accepted by the online nationality service ^[3].

The application is handled by the IRN ^[3]. If the applicant has a representative (a lawyer or solicitor registered in Portugal), submission is exclusively through the online channel (mandatory since 1 December 2023) ^[3]. Without a representative, the application may be sent by post or delivered at a Balcão da Nacionalidade (Nationality Counter) ^[3].

The application is assigned to a conservatória (registry office), automatically selected by the system, for review by the IRN ^[3].

What changed with Lei Orgânica n.º 1/2026?

The Lei da Nacionalidade was amended by Lei Orgânica n.º 1/2026, which entered into force on 19 May 2026 ^[1]. Art. 3 was amended by this lei orgânica ^[1]. Administrative proceedings that were pending on that date follow the previous wording of the law, in accordance with the transitional rule in art. 7 of LO 1/2026 ^[1].

Some of the amendments introduced by LO 1/2026 require complementary regulation, with a 90-day deadline for amending the Regulamento da Nacionalidade Portuguesa ^[3]. The justiça.gov.pt portal notes that its contents are being updated ^[3].

What does this article not cover?

• This article does not guarantee the granting of Portuguese nationality to anyone. The decision rests with the IRN on a case-by-case basis, based on the documents submitted and verification of the legal requirements.
• Processing times depend on the volume of cases and any further steps required by the IRN.
• If your marriage has a particularity — celebrated in a third country with doubt about its validity, a prior divorce not yet transcribed, or a question about your spouse's nationality — this article is not for you: the next step is to speak with a lawyer.

What is the next step?

If you are married to a Portuguese citizen and want to know whether you are entitled to nationality, tell us about your situation through the contact form. The response helps us understand whether the case is within the scope of Conecta Fronteiras and what documents might be needed. You may also write via WhatsApp.

This content is informational. It does not replace the analysis of your case.

Dra. Ana Paula Caldwell · OAB/RJ n.º 214.698 · OA Portugal n.º 61214P