Uniao de Facto (De Facto Union) in Portugal in 2026 - A Practical Guide to the Two-Year Rule, How You Prove It, the Tax, Housing and Social-Security Rights It Gives You, and Where It Stops Short of Marriage

Not every couple in Portugal wants to marry, and many do not need to. Portuguese law recognises the uniao de facto (de facto union), a status that grants long-term unmarried couples a broad set of the rights that marriage confers — in tax, housing, social security and immigration — without a ceremony, a registry appointment or a single euro in fees. It is one of the most useful and least understood parts of family law for foreigners living here. This guide explains how it works in 2026, how you prove it, and where it stops short of marriage.

What a uniao de facto is

Under Lei 7/2001, a de facto union exists where two people — of the same or opposite sex — have lived together "in conditions analogous to those of spouses" for more than two years. That is the whole test: two years of genuine shared life. Both partners must be at least 18, of sound mind, and not already married to someone else (unless legally separated), and they cannot be close relatives. Crucially, there is no register to join and no document to sign at the outset — the union simply comes into being by the fact of living together.

How you prove it

Because nothing is registered in advance, you prove a de facto union when you actually need to — to a tax office, a landlord, Social Security or an immigration desk. The standard proof is a declaration under oath by both partners together with an atestado de residencia (certificate of residence) from your junta de freguesia (parish council) confirming that you have shared an address for the required period. In practice, backing it up with aligned records — the same address on both partners' tax files, joint bills, a shared bank account — makes the union easy to demonstrate.

The rights it gives you

A de facto union carries real weight. Among the main protections under Lei 7/2001:

• Tax: de facto partners may opt for joint taxation (tributacao conjunta) on their IRS, exactly as a married couple can, if it works out better for them.
• The family home: the law protects the shared home, including the right of a surviving partner to remain in it and to have the tenancy transferred to them if the other partner dies or leaves.
• Social security: a surviving partner can claim a survivor's pension (pensao de sobrevivencia) from Social Security or the civil-service scheme, subject to proof of the union.
• Work and leave: in areas such as holiday scheduling and family leave, de facto partners are generally treated like spouses.
• Adoption: de facto couples have been able to adopt jointly since 2016.

Where it stops short of marriage

The union is not simply marriage by another name. The most important gap is inheritance: a de facto partner is not an automatic legal heir and does not enjoy the protected-heir (herdeiro legitimario) status a spouse has. The law softens this — a surviving partner has a temporary right to live in the shared home and use its contents, and can in some cases claim maintenance from the estate — but if you want your partner to inherit, you generally need a will. There is also no shared property regime: what each partner owns stays individually theirs, and there is no comunhao de adquiridos. And unlike marriage, the union confers no automatic next-of-kin standing in every context.

The immigration angle

For foreign residents this is significant. A de facto partner of a Portuguese citizen or a legal resident can, in principle, qualify for residence through family reunification (reagrupamento familiar), presenting proof of the union in the same way as any other benefit. For binational couples who are settled but unmarried, this is often the route that keeps them together legally.

How a union ends

A de facto union ends automatically when the couple separates, when one partner marries someone (or each other), or on the death of a partner. There is no divorce and no formal dissolution to file. But because the union is proven by facts rather than a certificate, disputes can arise about whether it still existed — and for how long — at the moment a right is claimed. Keeping simple evidence of your shared life is what settles those questions.

What this means for you

If you and your partner have lived together in Portugal for more than two years, you may already hold de facto-union rights without having done anything — but you only get the benefit when you can prove it. Get an atestado from your junta de freguesia, align your addresses on your tax records, and keep the paperwork. Then take one deliberate decision the union does not make for you: write a will, so that the partner the state already treats as your family in life is protected after your death too.