Nationality via marriage to Portuguese citizen (Art 3 n.1)

PT-MAR-01 is the marriage-based acquisition route: a foreign national married for more than three years to a Portuguese citizen may acquire Portuguese nationality by a declaration of will (declaração de vontade) made while the marriage subsists. It is an acquisition route (aquisição por efeito da vontade), located in Section I of Lei 37/81, and it confers acquired (not original / originária) nationality with effects from the date of the relevant act/registration (Art 12.º), in contrast with the ex tunc effect of attribution routes such as descent (Art 1.º).

Unlike the route's near-neighbours, marriage acquisition was one of the least disrupted provisions in the 2026 reform. The three-year base threshold is unchanged by Lei Orgânica 1/2026 ( PT-VC-013: this is the lowest-disruption route). The 2026 reform did, however, make two material changes:

1. A new Art 3.º n.4 makes acquisition by marriage (and by união de facto, the sibling route PT-MAR-02) conditional on the non-verification of Art 6.º n.1 alíneas f) to h) — the criminal/terrorism, security and UN/EU-restrictive-measures bars previously confined to naturalisation are now imported into marriage acquisition (PT-VC-013, NEW import).
2. The opposition (oposição) regime in Art 9.º was reformed so that the Ministério Público's effective-links assessment is now measured against the Art 6.º n.1 alíneas c) to i) yardstick, and the indeterminate "ostensiva rejeição / comportamentos" second part of Art 9.º n.1 a) was struck by the Tribunal Constitucional (TC Ac. 1133/2025) before re-enactment.

A foreign spouse who does not trigger the f)-h) bars, and who is either married for more than six years or has children of common Portuguese nationality, benefits from a statutory safe-harbour (Art 9.º n.2): the Ministério Público cannot oppose acquisition on the ground of absence of effective links (only the f)-h) criminal/security grounds remain available against them). This safe-harbour is preserved by LO 1/2026.

The Ministério Público's window to oppose acquisition runs for two years from the registration of the acquisition (Art 10.º n.1). This corrects the stale cascade-#12 corpus, which recorded a one-year window ( PT-VC-014: the window is 2 years, not 1 year).

Scope guard: This route covers acquisition by marriage (Art 3.º n.1). Acquisition by união de facto (de facto union, Art 3.º n.3), which requires prior judicial recognition of the union under Lei 7/2001, is a separate route documented at PT-MAR-02 and is not the subject of this dossier.

---

A foreign national qualifies under PT-MAR-01 if all of the following hold:

1. Valid marriage to a Portuguese citizen. The applicant is married to a person who holds Portuguese nationality at the relevant time. The Portuguese spouse's nationality may be original or acquired — Lei 37/81 does not distinguish for this purpose (and the executive may not read in an unlegislated "de origem"-only condition: STA Proc. 0219/10).

2. Duration > 3 years. The marriage has subsisted for more than three years (mais de 3 anos) at the time of the declaration. The three-year threshold is the base requirement and is unchanged by LO 1/2026.

3. Declaration during the marriage. Nationality is acquired mediante declaração (by declaration of will) made while the marriage subsists. There is no automatic acquisition by mere fact of marriage; the positive declaration is constitutive.

4. No Art 6.º n.1 f)-h) bar (Art 3.º n.4). None of the following is verified:

• f) a final conviction to a sentence of effective imprisonment exceeding 3 years (pena de prisão efetiva superior a 3 anos) for an enumerated category of crime (terrorism; violent or especially violent criminality; highly organised criminality; crimes against State security; aiding illegal immigration). This is a rebuttable presumption (presunção ilidível) assessed by the Ministério Público under Art 6.º n.14, weighing the nature/circumstances of the crime, time elapsed, rehabilitation and concrete integration. The threshold figure was corrected from the original "igual ou superior a 2 anos" to "efetiva superior a 3 anos" by Declaração de Retificação 17/2026/1 (PT-VC-008);
• g) the applicant constitutes a danger or threat to national security or defence (e.g. involvement in terrorism-related activities);
• h) the applicant is subject to UN or EU restrictive measures within the scope of Lei 97/2017 (this is the substantive successor to the now-revoked Art 13.º suspension-of-procedures mechanism — PT-VC-010).

Not imported into the marriage route: the naturalisation-only conditions — adulthood/majority a), the 7/10-year residence threshold b), the language + culture/history/symbols test c), the civics knowledge d), the solemn declaration of adherence to democratic principles e), and the subsistence-capacity requirement i) — do not apply as eligibility conditions to PT-MAR-01. There is no residence requirement and no language test for marriage acquisition. (The c)-i) battery re-enters only as the yardstick against which the MP measures effective links if it opposes under Art 9.º n.1 a) — see Requirements and Temporal Windows.)

Good-faith spouse protection (Art 3.º n.2). If the marriage is later declared null or annulled, a spouse who contracted it in good faith does not lose the nationality already acquired. This protects against retroactive unwinding where the applicant was unaware of a defect vitiating the marriage.

---

• Marriage to a Portuguese citizen, subsisting > 3 years at declaration.
• Positive declaração de vontade filed during the marriage.
• Non-verification of Art 6.º n.1 f), g), h) (Art 3.º n.4). The f) criminal bar operates as a rebuttable presumption (Art 6.º n.14).

The opposition layer (Art 9.º) — not an applicant requirement, a control filter

Acquisition by declaration is registered first and is then exposed to possible Ministério Público opposition within the statutory window. The applicant does not have to affirmatively prove "effective links" as a filing condition; rather, the absence of effective links is a ground on which the MP may oppose:

• Below the safe-harbour (≤ 6 years marriage and no common PT children): the MP may oppose for inexistência de laços de efetiva ligação à comunidade nacional (Art 9.º n.1 a)). Since LO 1/2026 the assessment is benchmarked against Art 6.º n.1 alíneas c) to i) (language/culture/history/symbols; civics; solemn-declaration adherence; criminal; security; UN/EU measures; subsistence) used as evaluative parameters of integration — not as automatic disqualifiers. The indeterminate second part of Art 9.º n.1 a) ("ostensiva rejeição / comportamentos") was struck by TC Ac. 1133/2025 and is not part of the operative text.
• At/above the safe-harbour (> 6 years marriage OR children of common Portuguese nationality): opposition on the absence-of-effective-links ground is barred (Art 9.º n.2). The only opposition grounds that survive against a safe-harboured applicant are the Art 6.º n.1 f)-h) criminal/security/sanctions grounds.

No-automatic-effect constraint (constitutional)

Any conviction-based opposition must be individually assessed, never an automatic effect of a criminal record (CRP Art 30.º n.4). This is the settled TC line: Ac. 331/2016 (Proc. 1155/2014, 19-05-2016) → Ac. 534/2021 → Ac. 127/2023 (Proc. 720/2022) → Ac. 846/2023, all striking the former automatic Art 9.º b) / Art 56.º n.2 b) RNP bar. LO 1/2026's rebuttable-presumption design (Art 6.º n.14) was drafted to comply with this line.

Documentary evidence (typical; subject to pending Regulamento)

• Applicant's birth certificate (certified/legalised + translated as required).
• Portuguese spouse's evidence of Portuguese nationality and the marriage certificate (assento de casamento) showing > 3 years' duration.
• Criminal-record certificates from Portugal and from the country/countries of nationality and habitual residence (feeding the Art 6.º n.1 f) assessment).
• For safe-harbour reliance: marriage certificate showing > 6 years, or birth certificates of common children showing Portuguese nationality.

---

1. Filing. The foreign spouse files the declaração de vontade to acquire nationality with the Instituto dos Registos e do Notariado (IRN) via the Conservatória dos Registos Centrais (CRC) — the single national registry for nationality acts. Filing is during the subsisting marriage (Art 3.º n.1).
2. Registration. The acquisition is registered. The "fact on which acquisition depends" for opposition-clock purposes is the declaração de vontade (per TC Ac. 768/2024, generalised by Ac. 522/2025).
3. Notification to the Ministério Público. Registration triggers the opposition layer: the MP is the organ competent to oppose acquisition (Art 9.º), and it must act within two years of registration (Art 10.º n.1).
4. Opposition (if any). The MP, if it opposes, files an opposition action before the administrative courts, asserting either (below safe-harbour) absence of effective links measured against Art 6.º n.1 c)-i), or (any case) an Art 6.º n.1 f)-h) bar. The assessment must be individualised (CRP Art 30.º n.4). If no opposition is filed within the window, or opposition fails, the acquisition consolidates.
5. Appeals. Decisions in nationality matters are challenged before the administrative courts, with the Supremo Tribunal Administrativo (STA) at the apex — not the civil courts / Supremo Tribunal de Justiça (this routing has applied since the LO 2/2006 modernisation). An applicant may also use the intimação para proteção de direitos, liberdades e garantias as a procedural remedy in acquisition matters (cf. STA Proc. 02630/23.3BELSB, 26-09-2024).

Authorities: Assembleia da República (legislator, reserva absoluta) · Ministério da Justiça · IRN / Conservatória dos Registos Centrais (CRC) (registration of the declaração) · Ministério Público (opposition organ) · administrative courts / STA (appeals) · Tribunal Constitucional (constitutional review of the framework). AIMA administers residence titles but is not the competent authority for marriage-based nationality acquisition (no residence condition applies). The Azores and Madeira confer no separate nationality and apply no different rules (CRP Art 225.º n.3; nationality is non-delegable State competence).

---

Constitutional competence. Nationality is the exclusive, non-delegable competence of the Assembleia da República under CRP Art 164.º f) (reserva absoluta), exercisable only by organic law (CRP Art 166.º n.2). The executive (and the future Regulamento) may implement but not supplement the organic law — confirmed by STA Proc. 0219/10 (0219/10.6BEPRT, 14-02-2019) and by the TC's repeated invocation of the reserva absoluta de lei parlamentar (TC Ac. 1133/2025). This is load-bearing for the route because it caps what the pending Regulamento may add to the marriage-acquisition procedure.

Provisions engaged by PT-MAR-01 (LO 1/2026 redação):

• Art 3.º n.1 — base acquisition right: a foreign national married more than 3 years to a Portuguese citizen may acquire nationality by declaration during the marriage.
• Art 3.º n.2 — good-faith protection: nullity or annulment (declaração de nulidade / anulação) of the marriage does not prejudice nationality acquired by a spouse who acted in good faith.
• Art 3.º n.4 — NEW cross-reference: acquisition under n.1 (and n.3) depends on the non-verification of Art 6.º n.1 f), g) and h) (criminal/terrorism conviction bar; serious-security-threat bar; UN/EU-restrictive-measures bar). Alíneas a)-e) and i) are NOT imported.
• Art 9.º n.1 a) — opposition ground: the Ministério Público may oppose acquisition for absence (inexistência) of effective links to the national community (laços de efetiva ligação à comunidade nacional). The reformed yardstick is Art 6.º n.1 c)-i). The former indeterminate "ostensiva rejeição / comportamentos" second part was struck by TC Ac. 1133/2025 (re-enacted without it).
• Art 9.º n.2 — SAFE-HARBOUR: no opposition lies where the marriage/união exceeds six years OR there are children of common Portuguese nationality, EXCEPT on the Art 6.º n.1 f)-h) grounds.
• Art 10.º n.1 — Ministério Público opposition window: two years from registration of the acquisition (the "fact on which acquisition depends" = the declaração de vontade per the TC line, below).

Loss is structurally separate. Successful MP opposition prevents the registered acquisition from consolidating — the nationality is treated as never validly acquired. This is conceptually distinct from loss of held nationality, which in Portuguese law arises only through Art 8.º voluntary renunciation by a dual national (see PT-XCT-01; there is no criminal-accessory-penalty loss after TC Ac. 1134/2025 struck CP Art 69-D).

---