Rents can be updated for January 2027, but the tenant can contest the increase if the landlord does not comply with the minimum advance notice required. In the general regime that applies when the parties have not stipulated another solution in writing, this deadline is 30 days, and there is no universal deadline of December 1 for all contracts. A late notice does not eliminate the landlord's right to update the rent later, but prevents the increase from being demanded without respecting the legally required deadline.
The deadline for communication depends on the rent due date, which should be checked in the contract. According to Article 1075 of the Civil Code, when rents correspond to calendar months, each rent after the first becomes due on the first business day of the previous month. Therefore, the rent for January may have to be paid in December, requiring that the communication be made with the required advance notice. Furthermore, communication must be made by registered letter with acknowledgment of receipt or delivered by hand with a receipt note; a merely verbal notice is not sufficient.
The communication must indicate the update coefficient used and the new rent amount; a vague indication that the rent will increase is not enough. Refusing or not collecting the letter does not guarantee that the increase will be void, as there are specific rules that consider communication to have been made even in these circumstances. It is also not enough to look at the month to which the payment refers – it is necessary to confirm when the first rent that the landlord intends to charge at the new value becomes due.
If the required advance notice is not respected, the tenant can contest the charge on the indicated date, but must continue to pay the legally owed rent to avoid contractual breach. The landlord can regularize the communication and demand the update for a later date. Increases not applied cannot be charged retroactively, but the coefficients can be incorporated into a later update provided no more than three years have passed. Before accepting or refusing the new amount, the tenant should cross-reference the communication with the contract and due date, keeping the letter and proof of receipt.
