Every autumn Portugal fixes the ceiling on how much a landlord may raise a sitting tenant's rent the following year. For 2027 it is 2.56%, a coefficient of 1.0256. Rents on new leases, meanwhile, are growing four times faster.

That gap is what matters for anyone who owns rental property here. This guide covers what the coefficient is, how to apply it correctly, and why a model that assumes the same rent growth for every flat will mislead you.

Key takeaways: The 2027 update coefficient is 1.0256, taken from the 12-month average CPI excluding housing to August 2026. Landlords must give at least 30 days' written notice, and the update is optional. New leases rose 10.2% year on year in Q2 2026 (INE), so sitting-tenant rents lag the market by about 7.6 points.

What is the 2027 rent update coefficient?

It is 1.0256, meaning a maximum rise of 2.56% for residential leases that qualify. The figure comes from the 12-month average of the consumer price index excluding housing, which INE reported at 2.6% for August 2026 and flagged as the reference for next year's rent update. The published coefficient, 1.0256, gives the precise 2.56%.

The formal coefficient is then published in the Diário da República by the end of October. This year's notice, Aviso n.º 24199/2026/2, is already out, and it confirms 1.0256 for the civil year 2027.

The recent run looks like this:

Legal rent update vs market rent growth 2024 update 6.94% 2025 update 2.16% 2026 update 2.24% 2027 update 2.56% New leases, Q2 26 10.2% Update = coefficient minus 1. Market = INE median rent of new leases, year on year. Sources: Portal da Habitação (2024-2026), Doutor Finanças / Diário da República (2027), INE (Q2 2026).

2024's 6.94% was the exceptional year, after the inflation spike. Since then the update has settled between 2.16% and 2.56%. It tracks last year's inflation; it does not track the rental market.

How does a landlord actually apply the update?

Three conditions matter, and each trips up small landlords. At least one year must have passed since the lease began or since the last update. The landlord must give written notice at least 30 days ahead. And the notice should state the coefficient used and the resulting new rent so the tenant can check the arithmetic.

The update is a right, not an obligation. Publishing 1.0256 does not raise anyone's rent automatically. A landlord can skip a year, apply it later, or agree something different in the contract, provided the lease allows it.

There is one forgiving rule, though it comes from a secondary source. Doutor Finanças reads the regime as saying that months already passed cannot be charged retroactively, but that skipped coefficients may be applied later, within three years of when each could first have been used. That is a consumer-site reading, not the statute, so confirm it with a lawyer before relying on it.

Older leases signed under previous rental regimes can follow different update mechanisms, and the tenant's contract is the first thing to read. Anything unusual, check with a lawyer or the Portal da Habitação. This article is general information, not legal or tax advice.

What does 2.56% do to a rent, and to the yield?

On a €900 rent the update adds €23.04 a month, taking it to €923.04, or €276.48 over a year. On €1,000 it is €25.60. Modest sums, but they compound.

Take an illustrative Lisbon T2 let at €1,200 a month, bought for €300,000, with operating costs we assume at 20% of rent. Those are our assumptions, not market data; swap in your own in the rental property calculator.

Before updateAfter 1.0256
Monthly rent€1,200.00€1,230.72
Annual rent€14,400€14,768.64
Operating costs (20%, then +3.6%)€2,880€2,983.68
Net operating income€11,520€11,784.96
Cap rate on €300,0003.84%3.93%

We assumed costs rise 3.6%, which is INE's flash estimate for September consumer price inflation (30 September 2026). Net income still climbs 2.3%, but it climbs slower than the 2.56% on the rent line, because costs grow faster than the cap. A landlord with a mortgage on a variable rate has it worse: see how Euribor moves change cash flow and the fixed versus variable comparison.

In short: The Portuguese rent update coefficient for 2027 is 1.0256, a 2.56% ceiling for sitting tenants, based on the 12-month average CPI excluding housing to August 2026. On a €1,200 rent it adds €30.72 a month. Landlords must give 30 days' written notice, and the update is optional.

Why the gap to market rents matters more than the coefficient

Because the gap decides which leases are worth keeping. INE's median rent for new leases hit €10.17/m² in the second quarter of 2026, up 10.2% on a year earlier and faster than the 9.1% of the first quarter. In Lisbon municipality the median was €17.79/m², up 5.1%, below the national pace. Almost 35,400 new contracts fed the figure.

Now stack that against the legal ceiling. The three updates for 2024, 2025 and 2026 compound to about 11.7% (1.0694 × 1.0216 × 1.0224). Market rents covered nearly the same ground in a single twelve-month stretch. Sized against each other: three years of capped updates (about 11.7%) roughly match one year of new-lease growth (10.2%), though the periods differ.

A caveat, since the periods differ. INE measures a national median of new contracts, not like-for-like rent on one flat, so the 10.2% is a direction and a scale, not a prediction for your tenant's unit.

Still, the logic holds. A tenant who has lived in a flat for years pays something close to the legal ceiling's compounding. A tenant who has just left would be replaced at something close to market. That is why landlords with stable tenants rarely feel the full rental boom, and why turnover, not the coefficient, is where yield changes hands.

It also changes what a fair comparison looks like. Our price-to-rent analysis shows prices rising faster than rents even on new leases. If sitting-tenant rents are capped at 2.56% against house prices up 16.5% (INE house price index, Q2 2026), existing landlords' yield on current value is shrinking quickly.

How to model rent growth in a deal

Split it in two. For the first lease, use the market rent you can evidence. For every year of that lease, use the coefficient (2.56% for 2027, and a conservative 2% to 2.5% beyond), not the market's 10%. For the next tenancy, reset to market, then let the coefficient run again.

Three habits prevent most errors:

  • Never extrapolate 10% rent growth. It describes new contracts nationally, and the legal cap blocks it for everyone already housed.
  • Check break-even, not just yield. If the update is below your cost inflation, your break-even rent drifts upward faster than the rent does. Test it with the break-even rent calculator.
  • Mind the tax rate. Category F rates depend on lease length and the year, so check the current schedule before pricing what an extra €25 a month is worth after tax. The Category F vs B analysis has the arithmetic.

If you hold several flats, treat each lease as its own asset with a start date and a last-update date. In a portfolio the oldest leases are the ones furthest from market, and they are the ones to review first. Our guide to building a rental portfolio covers how to lay that out.

Our verdict for 2027: apply the update every year you are allowed to, in writing, with the maths shown. Skipping it saves goodwill worth a few tens of euros a month and costs you compounding. Only skip it deliberately, with a tenant you want to keep for a reason you can name.

Sources

Frequently asked questions

How much can landlords raise the rent in Portugal in 2027?

By up to 2.56%, using the coefficient 1.0256. It derives from the 12-month average CPI excluding housing to August 2026 and applies to qualifying residential leases during the civil year 2027. A €1,000 rent can become €1,025.60.

How much notice must a landlord give for a rent increase?

At least 30 days in writing, stating the coefficient and the new rent. At least one year must also have passed since the lease started or since the last update. The contract can set different terms, so read the lease first.

Is the annual rent update mandatory?

No. Publishing the coefficient does not change any rent on its own. A landlord can skip or delay the update. Missed months cannot be charged retroactively, but skipped coefficients may be applied later; check the lease and the law first.

How does the 2.56% cap compare with market rents?

It is far lower. INE reports that the median rent on new leases rose 10.2% year on year in Q2 2026. Sitting-tenant rents are capped near inflation, while a re-let can reset to market, which is why turnover drives yield.