Joint custody and alternating residence in Portugal

The difference is simple to state: what is commonly called *guarda partilhada* or *guarda conjunta* — the Portuguese terms usually rendered in English as "joint custody" or "shared custody" — corresponds, under Portuguese law, to the joint exercise of parental responsibilities. That is the general rule of article 1906 of the Portuguese Civil Code, and it applies even when the child lives with only one parent. *Residência alternada* (alternating residence) is something else: it means the child lives alternately with each parent, a residence arrangement the court may order when it serves the best interests of the child (article 1906(6) of the Civil Code).

This terminological confusion has real consequences: many parents believe they already have "joint custody" when what they have is simply the joint exercise of parental responsibilities that the law imposes by default — and others assume that alternating residence requires the other parent's agreement, which stopped being true in 2020. This article sorts out the concepts and their practical effects.

Key points

• Portuguese law does not use the terms *guarda partilhada* or *guarda conjunta* ("joint custody" / "shared custody") — it speaks of parental responsibilities and of residence.
• The joint exercise of parental responsibilities in matters of particular importance is the general rule (article 1906 of the Civil Code), even when the child resides with only one parent.
• Alternating residence (*residência alternada*) is a residence arrangement: the child lives alternately with each parent (article 1906(6) of the Civil Code, as amended by Law no. 65/2020).
• The court may order alternating residence even without the parents' agreement, when it serves the child's best interests.
• Practical effects: the child may appear as a dependant on both parents' Portuguese income tax (IRS) returns, the family allowance may be split, and child support does not automatically disappear.

What the law says: parental responsibilities, not "custody"

Since 2008, the Portuguese Civil Code has replaced "paternal power" (*poder paternal*) with parental responsibilities and abandoned the language of "custody" (*guarda*). Article 1906 organises the matter on two distinct planes: who decides (the exercise of parental responsibilities) and where the child lives (residence). It is the overlap of these two planes that generates the confusion between "joint custody", "shared custody" and alternating residence.

On the decision-making plane, the rule is joint exercise: matters of particular importance in the child's life — significant surgical interventions, choice of school, relocation abroad — are decided by both parents, unless a court rules otherwise based on the child's interests. Day-to-day matters fall to the parent with whom the child is residing or staying at the time. Anyone asking about the "difference between joint custody and shared custody" is, in practice, comparing two everyday labels for realities that the law treats as a single regime under this article.

What alternating residence is

Alternating residence means that the child lives alternately with each parent, in defined periods — alternating weeks is the most common model, but there are others. Since Law no. 65/2020, article 1906(6) of the Civil Code has expressly provided that the court may order alternating residence when it serves the best interests of the child, weighing all the relevant circumstances — and it may do so regardless of whether the parents mutually agree.

In the concrete assessment, the courts weigh, among other factors, the child's age, the proximity between the parents' homes and between these and the school, each parent's actual availability for the child's daily life, the quality of the child's relationship with each parent, and a minimum capacity for communication between the parents. Portuguese case law has stressed that conflict between the parents is not, in itself, enough to rule out alternating residence — otherwise, it would suffice for one parent to fuel the conflict in order to block it.

What rules out alternating residence

Alternating residence is ruled out by anything that, in the specific case, makes it contrary to the child's interests. The most common obstacles are geographical distance — homes in different cities, or so far apart that alternation would force the child to change school routines every week —, the actual unavailability of one of the parents (incompatible schedules, prolonged absences), specific needs of the child requiring added stability, and the complete lack of habitable conditions in one of the homes.

There is also an express legal limit: in cases of domestic violence and other situations of danger, article 1906-A of the Civil Code sets aside the rule of joint exercise — and, by even stronger reason, alternating residence — when it would be contrary to the child's interests, namely where one of the parents has been convicted of, or is formally under investigation for, crimes against the physical integrity or liberty of the other parent or of the child.

Practical effects: income tax, family allowance and child support

Income tax (IRS): a dependant on both returns

Where there is joint exercise of parental responsibilities with alternating residence, the child may be included as a dependant on both parents' Portuguese income tax (IRS) returns. For this, the alternating residence arrangement must be reported to the Portuguese Tax Authority through the Portal das Finanças, as a rule by 15 February of the year following the tax year concerned. Once the alternation has been reported, the tax deductions relating to the dependant are split between the two households, under article 78 of the IRS Code — in equal shares, or in the expense percentages the parents report.

Family allowance split between parents

The family allowance (*abono de família*) may be split in equal shares between the two parents when the child is in alternating residence. The split is not automatic: it must be requested from Social Security, with proof of the arrangement in place (a court-approved agreement or a judicial decision). Without that request, the allowance continues to be paid in full to the parent who applied for it.

Child support under alternating residence

Alternating residence does not, in itself, eliminate child support (*pensão de alimentos*). When the parents' incomes are equivalent, it is common for each to cover the child's expenses during their own periods, splitting health and education expenses in half. But where there is a significant economic imbalance, a support payment may be set at the expense of the parent with greater means, so that the child maintains an equivalent standard of living in both homes — maintenance continues to be measured by the child's needs and each parent's means (article 2004 of the Civil Code).

How it is established — and what to do in case of disagreement

Alternating residence may be established by agreement between the parents — at the Civil Registry Office or approved by the court — or by decision of the Family and Minors Court in parental responsibilities regulation proceedings, which follow the RGPTC framework (Law no. 141/2015). If a regulation with single residence already exists and circumstances have changed, it is possible to apply for a modification of the arrangement (article 42 of the RGPTC). And if the arrangement in place is not being complied with — obstructed contact, failed residence handovers —, the route is the non-compliance procedure.

FAQs

What is the difference between "guarda partilhada" and "guarda conjunta" (joint and shared custody)?

Neither expression appears in current Portuguese law. What the law provides for is the joint exercise of parental responsibilities in matters of particular importance — the general rule of article 1906 of the Civil Code, even when the child resides with only one parent — and, on a distinct plane, alternating residence, in which the child lives alternately with each parent.

How does joint custody work in Portugal?

What is usually being asked is how alternating residence works: the child spends broadly equivalent periods with each parent — for example, alternating weeks — while both retain the joint exercise of parental responsibilities. Day-to-day matters fall to the parent with whom the child is staying at any given time.

What does alternating residence mean?

It means the child resides alternately with each parent, in periods defined in the regulation arrangement. The court may order it when it serves the best interests of the child, weighing all the relevant circumstances, even without the parents' agreement (article 1906(6) of the Civil Code, as amended by Law no. 65/2020).

What rules out alternating residence?

Anything that makes it contrary to the child's interests in the specific case: significant distance between the parents' homes or between these and the school, the actual unavailability of one of the parents, specific needs of the child incompatible with alternation, and situations of domestic violence or danger (article 1906-A of the Civil Code). One parent's disagreement, on its own, does not rule it out.

How is alternating residence reported for Portuguese income tax (IRS)?

The alternating residence arrangement must be reported by both parents to the Portuguese Tax Authority through the Portal das Finanças, as a rule by 15 February of the year following the tax year concerned. Once reported, the child may be included as a dependant on both returns, with the tax deductions split under article 78 of the IRS Code.

How does the family allowance work under joint custody?

The allocation or sharing of family allowance in alternating residence depends on the applicable Social Security procedure and on the parental agreement or court decision. It should not be presented as an automatic equal split paid directly by Social Security.

Is there child support under alternating residence?

There can be. Alternating residence does not automatically dispense with child support: where the parents' incomes are unbalanced, a support payment may be set at the expense of the parent with greater economic capacity, in addition to the sharing of health and education expenses, to ensure the child an equivalent standard of living in both homes.