The figure is, for the time being, an estimate, as there will not be greater certainty regarding the annual rent adjustment percentage for 2027 until 10 September.

By law, house rents may be adjusted annually, based on the annual rent adjustment coefficient set by the INE, which is based on the average inflation rate over the last 12 months. The data, which is currently provisional, indicates that the rent increase is expected to stand at 2.51 per cent.

Between September and October, INE calculates and publishes the coefficient in the Official Gazette, after which landlords may apply the new rate from January of the following year.

If these figures are confirmed, the rent increase for 2027 will be even higher than the annual rate set for 2026 (2.24 per cent). The reasons for this are linked to the rise in inflation in Portugal, which occurred in March and reflects the increase in energy prices caused by the conflict in the Middle East.

In other words, rents under tenancy agreements that will remain in force in 2027 may rise. According to the calculations, a rent of €1,000 could be increased by €25.1 as early as next year.

When can the rent adjustment be applied?

Landlords may carry out an annual rent adjustment once the tenancy agreement has been in force for one year, although they are subject to the notice periods laid down by law.

The rent adjustment, based on the INE coefficient, also applies to tenancy agreements dating from before 1990 that have not transitioned to the New Urban Tenancy Regime.

However, please note that the increase is not automatic. To adjust the rent, the landlord must send a registered letter with acknowledgement of receipt (or deliver it in person against a signed receipt

To confirm the rent increase, the landlord must send their tenant a registered letter with acknowledgement of receipt, stating the coefficient applied. The letter must also state the updated amount, as well as the date on which payment is due to commence.

Notices of rent increases sent by email, text message or ordinary letter will have no legal validity.