Child Maintenance Guarantee Fund
When the parent ordered to pay does not pay, the Portuguese State can step in, up to one IAS per debtor.
The maintenance figure is the one in the agreement or the court decision. Household income is that of the home the child lives in, and the law does not divide it by headcount: it uses a scale where the applicant weighs 1, each adult 0.7 and each minor 0.5 (article 5 of Decree-Law 70/2010).
The Fund pays forward and does not pay arrears. Payment starts in the month after the court decision is notified, with no payment of instalments already due (article 4(4) and (5) of Decree-Law 164/99): the months already missing remain the parent's debt. That is the strongest reason not to wait.
What this calculator shows is the MAXIMUM the Fund can pay, not what it will pay: the court sets the amount having regard to the household's economic capacity, the maintenance set and the child's needs, so it may set less. Out of scope: the full means-test income definition, the judicial fixing itself, and the garnishment of the debtor's wage, which has its own calculator. 2026 values (IAS of 537.13 €).
This is an educational estimate and does not constitute legal or financial advice.
The State pays instead of the debtor, not alongside them
Article 1(1) of Law 75/98 provides that where a person judicially ordered to pay maintenance to a minor resident in Portugal fails to pay the amounts owed through the ordinary enforcement route, and the child has no gross income above the social support index (IAS) and does not benefit to that extent from the income of the person in whose care they are, the State secures the payments provided for in that law until the obligation actually begins to be met. That single sentence carries three conditions: a judicially fixed obligation exists, it is not being met through normal enforcement, and the child has no means of their own above a threshold. The payer is the Fundo de Garantia dos Alimentos Devidos a Menores, managed in a special account by the Social Security Financial Management Institute, and payment is made on the order of the competent court rather than on a direct administrative application.
The ceiling is per debtor, not per child, and this is where most figures fail
Article 2(1) of Law 75/98 is explicit: the payments are fixed by the court and cannot exceed, monthly, per debtor, the amount of one IAS, regardless of the number of minor children. Article 3(5) of Decree-Law 164/99 repeats it word for word. Read the two phrases slowly, because they decide the number: "per debtor" and "regardless of the number of minor children". A father who owes maintenance for three children does not generate three ceilings of 537.13 €; he generates one. If the court had set 300 € per child, that is 900 € a month, the Fund cannot pay more than 537.13 € in total, which works out at 179.04 € per child, and the remaining 362.87 € stays the debtor's liability. That is the opposite of the intuitive reading and the opposite of what many published summaries suggest, which is why this calculator asks how many children the same debtor owes.
The second ceiling: the Fund never pays more than the court set
There is a second limit, and the lower of the two always governs. Article 4-A(1) of Law 75/98, added by Law 71/2018, provides that the amount of maintenance borne by the Fund cannot exceed the maintenance established in the agreement or in the judicial decision regulating parental responsibilities or fixing maintenance. So if the maintenance was set at 150 €, the Fund pays 150 € and not 537.13 €: the one-IAS ceiling is a maximum, not a guaranteed amount and not a floor. Where update coefficients were set for the maintenance, paragraph 2 of the same article requires them to be taken into account provided the calculation can be performed by simple arithmetic using publicly known coefficients, and paragraph 3 states that the Fund applies the update of its own motion when the conditions are renewed.
The means test measures per-capita income, not total income
The law requires that the child has no gross income above one IAS and does not benefit to that extent from the income of the person in whose care they are, and article 3(2) of Decree-Law 164/99 translates that into arithmetic: the child is taken not to benefit from another person's income above the IAS where the per-capita income of the household is not above that value. Per-capita here is not a division by headcount. Paragraph 3 refers to Decree-Law 70/2010, whose article 5 sets an equivalence scale: the applicant weighs 1, each adult weighs 0.7 and each minor weighs 0.5. Paragraph 4 identifies the applicant for this purpose as the child's legal representative or the person in whose care the child is. In a household of a mother and two minor children the weighting is 1 + 0.5 + 0.5 = 2, so an income of 900 € gives a per-capita figure of 450 € rather than 300 €. Dividing by heads produces a lower number than the law requires and makes people look eligible when they are not. Note also the wording "not above": a per-capita figure of exactly 537.13 € still qualifies.
The Fund pays forward and does not pay arrears
This is the second expectation the scheme overturns. Article 4(4) of Decree-Law 164/99 states that the Social Security Financial Management Institute starts paying, on the Fund's account, in the month following notification of the court decision, and that there is no payment of instalments already due; paragraph 5 adds that the payment is owed from the first day of the month following the court decision. Anyone expecting the State to cover the missing months will not find that in the law: instalments already due remain the parent's debt and must be recovered from them, typically through enforcement and garnishment. In practice every month of delay before applying is a month nobody pays, and that is the strongest argument for applying early. Note too that article 3(6) of Law 75/98 requires annual renewal of proof that the conditions still hold, failing which the payment ceases, and that article 3(6) of Decree-Law 164/99 excludes minors placed in State-funded social support establishments, reception centres, educational guardianship centres or detention centres.
Worked example
Take a mother living with two minor children and a household income of 900 € a month. The weighting is 1 for her plus 0.5 for each child, that is 2, so the per-capita income is 450 € a month, below the 537.13 € limit for 2026, so the means test is met. The court had set maintenance of 250 € a month payable by the father, who stopped paying. Because 250 € is below the 537.13 € ceiling, the Fund can secure the maintenance in full: 250 € a month, 3000 € a year. Now change one input: if the father owed 300 € for each of the two children, that is 600 € a month, the ceiling bites, because it is per debtor and not per child. The Fund would pay at most 537.13 €, which is 268.57 € per child, and the remaining 62.87 € would stay the father's debt. In neither case does the Fund pay the months already due before the court decision.
Frequently asked questions
How much does the Portuguese child maintenance guarantee fund pay?
Is the 537.13 € ceiling per child or per debtor?
Who qualifies? Is there an income limit?
Does the Fund pay maintenance that is already in arrears?
How do you apply, and how long is it paid for?
Does the debtor stop owing the money?
Are the calculator figures exact?
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Sources
- Lei n.º 75/98, de 19 de novembro: garantia dos alimentos devidos a menores · Procuradoria-Geral Distrital de Lisboa
- Decreto-Lei n.º 164/99, de 13 de maio: regula a garantia de alimentos devidos a menores · Procuradoria-Geral Distrital de Lisboa
Author: Thorben Rasmus Idel · Reviewed by: Nahar Geva · Last reviewed: 2026-08-18