Short answer. No, not unilaterally. A fixed-term lease fixes the rent for that term, and the lessor cannot change it mid-term without your agreement. The exposure comes at the end of the term: if you stay on and the lease renews by operation of law, the renewal runs on a short period, not the original one.

What the law says

it is understood that there is an implied new lease, not for the period of the original contract, but for the time established in articles 1682 and 1687

Civil Code, Article 1670 — Implied New Lease (Tacita Reconduccion). Read the full provision →

What the law says

The other terms of the original contract shall be revived.

Civil Code, Article 1670 — Implied New Lease (Tacita Reconduccion). Read the full provision →

Inside the term, the contract governs

A lease is a contract, and the rent is one of its terms. Neither party can rewrite a term of a subsisting contract on their own, so a lessor who announces a higher rate three months into a one-year lease is making an offer, not exercising a right. A tenant who keeps paying the new figure without objecting may later be treated as having accepted it, which is why the response should be in writing and should say plainly that you are paying the contracted rent under the existing lease. What you write during those weeks tends to matter more than what you feel about it.

The fifteen days after the term ends

Article 1670 covers what happens when a lease simply runs out and nobody moves. If the lessee continues enjoying the property for fifteen days with the lessor's acquiescence, and neither party gave notice to the contrary beforehand, it is understood that there is an implied new lease, not for the period of the original contract, but for the time established in articles 1682 and 1687. The renewal is not another year merely because the first contract ran a year. It runs for the period the law fixes for that kind of lease, which for rent paid monthly is month to month.

What a revived lease carries over

The article adds that the other terms of the original contract shall be revived, so the rent does not jump on its own when a lease renews this way. It continues at the agreed figure, along with the rest of the terms. The change is in duration, and that is what exposes a tenant: a short renewal period means the lessor reaches a lawful end point every month, and at each of those the rent can be renegotiated or the lease simply not continued. Security of the original term is what has been lost, not the rate itself.

What to check now

Read the lease for an escalation clause, because a rent increase written into the contract in advance is not a unilateral change at all, and many leases carry one. Note the end date and how much advance notice each side has to give. If the term has already lapsed and you are still in the unit, work out what kind of lease you are now in and on what period. Where the property is residential and the rent modest, rent control legislation may also cap increases and set notice requirements, so check whether it covers your unit before conceding anything.

Cases citing this provision

These Supreme Court decisions cite the provision above. We list them so you can read them yourself; the summaries of what each decided are not ours to give.

Related provisions

Note. Statute text quoted on this page is reproduced from the official enactment and is linked to the full provision. The explanation around it is general legal information from Vivas & Nobles Law Office, not legal advice. Whether it applies to your situation depends on facts only a lawyer reviewing them can assess.