Portugal's supported-rent regime: how the law sets the rent

The rent comes from a formula, not from a negotiation

Article 21 of Law 81/2014 is short and it is the heart of the regime: the rent under the supported-rent regime is determined by applying an effort rate to the household's corrected monthly income, the effort rate (T) being the value, rounded to the thousandth, that results from the formula T = 0.067 × (RMC/IAS)¹.

Notice what that means. The rent is not a fixed percentage of income, which is what almost everyone assumes on hearing the words "effort rate". The percentage is itself a function of income: the higher the corrected income, the higher the rate applied to it. Since the two are then multiplied, the rent grows with the square of income rather than in proportion to it.

An example makes it visible. On a corrected income of 500 € the rate is 0.062 and the rent is 31.00 €, or 6.2 % of income. At double that, 1,000 €, the rate becomes 0.125 and the rent 125 €, that is four times as much for twice the income. This design is what makes social housing weigh very little on those who have very little, and it is why there is no table of rents: there is a curve.

The social support index stands at 537.13 € in 2026, and it is the only piece of this formula that changes every year.

The starting income is net, and that changed in 2016

The point where most published material goes wrong is the first one. Article 3(f), in the wording in force, defines net monthly income (RML) as one twelfth of the sum of the annual net incomes of all members of the household, and paragraph 2 of the same article says exactly where to find the figures: the rendimento global and the coleta líquida as they appear on the personal income tax return validated by the Portuguese tax authority for the previous year².

Those are two specific boxes: the rendimento global, which is box 1 of the tax assessment note, and the coleta líquida, which is box 22 of the assessment table. The difference between them, divided by twelve, is the RML.

The original 2014 wording was different. It spoke of gross monthly income (RMB), defined as one twelfth of the total gross annual income earned by all members of the household¹. It was Law 32/2016 that swapped gross for net, with effect from 1 September 2016². A page written before that date is not describing an alternative regime: it is computing the rent from a number the law no longer uses, and the error is large, because the net tax due of a household with taxable income can be several percentage points of its gross income.

The seven deductions, and the two that are almost always added up wrongly

Article 3(g) defines the corrected monthly income as the net monthly income less the amounts listed there, and these are they, verbatim²:

• 10 % of the social support index for the first dependant;
• 15 % of the social support index for the second dependant;
• 20 % of the social support index for each dependant beyond the second;
• 10 % of the social support index for each disabled member, which is added to the previous items if that person also falls within the definition of dependant;
• 10 % of the social support index for each member of the household aged 65 or over;
• 20 % of the social support index in the case of a single-parent family;
• the amount produced by applying the per-capita factor in Annex I to the social support index.

The first thing that goes wrong is the reading of the first three items. They are cumulative. Three dependants do not deduct 20 %: they deduct 10 % plus 15 % plus 20 %, that is 45 % of the index, which in 2026 is 241.71 €. Four dependants deduct 65 %, and so on, twenty percentage points for each one.

The second is the nature of the per-capita factor. The first six items look at who the household members are; the seventh looks only at how many there are, and it is an additional amount, not an alternative. Annex I, referred to by article 3(d), is this²:

A five-person household with three dependants therefore deducts 45 % for the dependants and a further 14 % for the per-capita factor, adding up to 59 % of the index, or 316.91 €.

There is a third, quieter trap: the 65-and-over item was 0.05 in the 2014 wording and the text republished by Law 32/2016 raised it to 10 %¹². It was doubled. Any sum predating September 2016 understates the deduction of a household with a pensioner.

The 23 % cap is new, and it is where the curve straightens

Left to itself, the article 21 formula would make the rent rise indefinitely. Law 32/2016 added article 21-A precisely to brake it: the maximum effort rate may not exceed 23 % of the tenant household's corrected monthly income².

Working backwards, the formula's rate reaches 23 % when the corrected income reaches 0.23 divided by 0.067 times the index, that is about 1,843.88 € in 2026. Below that the rent grows faster than income; above it the rent grows in a straight line again, at 23 % of each additional euro of corrected income.

It is worth recording what disappeared at the same time. Paragraph 3 of article 22 allowed the landlord entity, for planning reasons and where the characteristics of the property permitted it, to apply a higher maximum rent, corresponding to an effort rate of up to 25 % of the corrected income, with phasing. Law 32/2016 repealed it². Today the only ceiling is the conditioned-rent one, which the next section covers.

The 5.37 € floor and the ceiling that depends on the value of the home

Article 22 closes the sum from both sides, and the two ends are of very different natures.

The floor is simple and absolute: the rent under the supported-rent regime may not be lower than 1 % of the social support index in force at any given moment¹. In 2026 that is 5.37 € a month. There is no condition attached, which means that a household whose deductions exceed its income, and which therefore has a negative corrected income and an effort rate of zero, still pays those 5.37 €.

The ceiling requires a trip through two other statutes. Article 22(2) says only that the maximum rent under the supported-rent regime is the maximum rent applicable to residential tenancies under the conditioned-rent regime¹. That regime is the one in Law 80/2014, published on the same day, whose article 3(1) says the rent may not exceed one twelfth of the product of the conditioned-rent rate and the property tax value of the dwelling in the year the contract is signed, and whose paragraph 2 sends the rate to a ministerial order³. That order is Portaria 236/2015 of 10 August, and its article 1 is a single sentence: the conditioned-rent rate referred to in article 3(2) of Law 80/2014 is fixed at 6.7 %⁴.

Putting the three pieces together: the maximum rent is the home's property tax value times 6.7 %, divided by twelve. On a home with a tax value of 45,000 € that is 251.25 € a month, and no level of household income can take the rent above it. That is also why the tax value appears among the fields of the official simulator and of our calculator: without it there is no ceiling to apply.

The IHRU still lists that 2015 order as the legislation in force for the conditioned-rent regime⁵, so unlike the social support index the rate is not revised every year.

A divergence between the law and the official simulator

The IHRU publishes a simulator of the regime, and it is the tool practically every tenant turns to⁵. It gets the whole structure right: it uses net income, asks for the rendimento global and the coleta líquida, applies the per-capita factor exactly as Annex I defines it, caps the rate at 23 %, applies the 1 % index floor and the ceiling of the tax value times 6.7 % divided by twelve, and even carries the correct 2026 index, 537.13 €.

There is one point at which it departs from the law, and it is the per-dependant deductions. The spreadsheet the simulator runs in the browser handles the number of dependants with the line (0.25 + v_ci_dependentes-2*0.20), and that expression is not the law's for two independent reasons: it is missing the brackets item (iii) requires, because what the law adds up is 0.25 plus (dependants minus two) times 0.20, and the form field is not converted to a number before entering the sum. Checked on 3 September 2026, the combined effect is that from the third dependant onward the simulator applies a deduction of about minus 79 € instead of the hundreds of euros the law requires.

Because a smaller deduction leaves a larger corrected income, and the corrected income enters the sum twice, the difference in the final figure is not small. For the household in our worked example, a couple with three children, 15,000 € of gross taxable income, 300 € of net tax due and a home worth 45,000 €, the law gives a rent of 102.61 € a month and the official simulator returns 188.00 €, a difference of 85.39 € a month, or 1,024.68 € a year.

Two caveats, because they matter. The first is that the simulator's own page warns that the rent values it presents are indicative, and the rent actually paid is the one the landlord entity sets with its own system, which may well compute correctly: what is compared here is the law against a support tool, not against a bill. The second is that a divergence observed on one date can be corrected at any time, in which case this section stops describing the present. Our calculator follows the law, and that is why it flags cases with three or more dependants expressly.

What the law decides, and what it does not

Two questions usually arrive together and have very different answers. How much will I pay is arithmetic, and it is what this page and the calculator handle. Whether I am entitled to a home is not: article 6 lists the impediments, among them owning, holding a usufruct over or renting another urban dwelling, or already receiving public financial support for housing, and allocation is by competition, to the applicants best ranked according to the ranking and weighting criteria set for that purpose by the entity itself¹. No formula predicts how many homes exist or how many applicants are ahead of you.

Also outside this calculation are the full legal definition of annual net income beyond the two boxes the law names, the case of a household that legally filed no tax return, the phasing of article 37 when a revision raises the rent, and the annual update, which article 23 sends to article 1077(2) of the Civil Code, that is to the same coefficient that updates any residential rent.

Finally, a note that changes the reading of everything above when the landlord is a municipality. Article 3(4) allows the autonomous regions and local authorities to approve their own regulation, adapted to the realities of the neighbourhoods they own, and paragraph 5 imposes a clear limit on it: that regulation may not lead to regulatory rules less favourable to tenants, whether as to the calculation of rents or as to the guarantees that the tenancy is maintained². What the law computes is therefore a maximum: a municipal regulation may charge less, never more.