You signed your lease a year ago, and now a letter from the landlord announces a rent increase. Surprise, annoyance, sometimes confusion: is this really legal? Rent revision during a lease is one of the topics that most strains the landlord-tenant relationship. Yet, the rules are fairly clear. You just need to know where to look in your contract and how to verify the calculation.
This article explains when revision is possible, how it is calculated, which clauses to watch out for, and how to react if something seems off. We stay practical, with real-life examples.
The 30-Second Answer
Your rent can only be revised during a lease if your contract contains a revision clause that explicitly provides for it. This revision is based on the rent reference index (IRL), published quarterly by INSEE. It occurs once a year, on the lease anniversary date (or another date specified in the contract). The landlord cannot revise the rent retroactively: if they forget to do so one year, they cannot catch up on previous years. Finally, the new rent can never exceed the one-year variation of the IRL.
Unsure about the clause in your lease or the amount requested? Upload your contract to bail.immo to quickly check whether the revision is valid and the calculation is correct.
What the Law Says
Rent revision during a lease is governed by Law No. 89-462 of July 6, 1989 aimed at improving landlord-tenant relations. This is the reference text for unfurnished and furnished rentals used as primary residences.
The principle is simple: no revision clause, no possible increase. If your lease does not mention revision, the rent remains fixed for the entire duration of the contract, including during tacit renewals. This is what ANIL reminds us: in the absence of a written lease or a revision clause, the landlord cannot revise the rent.
When the clause exists, revision follows precise rules:
- The reference index: This is the IRL, published quarterly by INSEE. It corresponds to the twelve-month average of consumer price changes, excluding tobacco and rents.
- The revision date: Generally, this is the anniversary date of the lease signing. However, the contract may provide for another date, provided it is clearly indicated.
- The calculation: New rent = current rent × (IRL of the revision quarter ÷ IRL of the same quarter of the previous year).
- Non-retroactivity: If the landlord has not revised the rent on the scheduled date, they cannot claim past increases. The revision only applies going forward.
Note: The revision only applies to the rent excluding charges. Service charge provisions, on the other hand, evolve according to actual expenses and the annual adjustment, not the IRL.
Why This Can Be Problematic
On paper, everything seems simple. In real life, difficulties often arise from details that no one checked at the time of signing.
First pitfall: a poorly drafted clause. Some leases mention a revision "according to the INSEE index" without specifying which one, or refer to an index that no longer exists. Others provide for an "automatic" revision without indicating a date. An imprecise clause can be challenged, but you need to act quickly.
Second pitfall: the wrong starting index. The calculation must compare the IRL of the revision quarter with that of the same quarter of the previous year. If the landlord uses a different quarter, the result is wrong. For example, a lease signed in March 2024 with a revision in March 2025 must compare the IRL of Q1 2025 with that of Q1 2024. Using the IRL of Q4 2024 skews the calculation.
Third pitfall: late revision. Your landlord announces in September an increase "for the past year" when the anniversary date was in March. They cannot claim the past six months. The increase can only apply from the date of their request, and only if the clause allows it.
Fourth pitfall: confusion with the surcharge for work. Some landlords present an increase as a "revision" when it is actually a surcharge for property improvements. This is a completely different regime: the surcharge for work requires written agreement between the parties, or a court decision, and it is subject to other caps.
Let's take a concrete example. You rent an apartment for €700 excluding charges since June 1, 2024. Your lease contains an annual revision clause on the anniversary date. In June 2025, the landlord announces a new rent of €735. You check: the IRL for Q2 2025 is 145.20, and for Q2 2024 it was 141.03. The calculation gives 700 × (145.20 ÷ 141.03) = €720.70. The requested €735 is too high. You are entitled to contest it.
Another situation: your lease contains no revision clause. The landlord still announces an increase "to keep up with inflation." This is illegal. You can refuse in writing and continue paying the initial rent.
Exceptions to Know
Not all leases are treated equally. Here are the main nuances.
Mobility lease. The mobility lease, lasting 1 to 10 months, is non-renewable and the rent cannot be revised during the lease. Any revision clause is prohibited.
Social housing (HLM). The revision rules are different. The rent for subsidized housing evolves according to specific rules set by HLM regulations, not the lease clause.
Tense areas and rent control. In Paris, Lille, Lyon, Villeurbanne, Bordeaux, or municipalities subject to rent control, the revision cannot lead to exceeding the increased reference rent. If the initial rent was already at the cap, the revision may be limited or even impossible.
Commercial or professional leases. The revision rules are different: they fall under the commercial code or specific agreements, not the law of July 6, 1989.
Furnished rentals. The revision follows the same principles as for unfurnished rentals, provided the lease is subject to the 1989 law (primary residence). The revision clause must be present, and the calculation uses the IRL.
Checklist: What to Check Before Accepting an Increase
- Does your lease contain a revision clause? If not, refuse the increase in writing.
- Does the clause specify a precise index and a revision date? If it is vague, it can be challenged.
- Is the revision date respected? No revision before the anniversary date, unless there is an explicit contrary clause.
- Is the calculation accurate? Check the IRL used and compare it with the same quarter of the previous year.
- Does the increase not exceed the IRL variation? If so, contest the excess.
- Is the landlord not claiming arrears? Revision is not retroactive.
- Is your home in a rent-controlled area? Check that the new rent does not exceed the allowed cap.
If any of these points seem doubtful, do not pay the increase without verifying. You can ask the landlord for the calculation details in writing. If they refuse or maintain an unjustified increase, you can refer the matter to the departmental conciliation commission (free) or the judge for protection disputes.
Possible Actions in Case of Disagreement
1. Ask for explanations. Send a registered letter to the landlord requesting the calculation details and the legal basis for the increase. Keep a copy.
2. Refuse the increase. If the clause is absent or the calculation is wrong, notify your refusal in writing, explaining why. Continue paying the current rent.
3. Refer to the conciliation commission. This is a free and often quick step. It can help reach an agreement without going to court.
4. Refer to the judge for protection disputes. As a last resort, the judge can cancel the increase, order the landlord to reimburse overpayments, or even award damages.
Before it gets to that, a careful review of your lease can save you a lot of trouble. On bail.immo, you can analyze your contract and spot dubious revision clauses in minutes.
FAQ
Can my landlord revise the rent without a clause in the lease? No. Revision is only possible if the lease contains an explicit clause. Without a clause, the rent remains unchanged for the entire duration of the lease.
Is the revision automatic every year? No. The landlord must express their intention to revise. If they do not do so by the scheduled date, they lose the benefit of the revision for the past year.
Can I contest an increase already paid? Yes, if the increase was irregular. You can request a refund of the overpaid amounts, within the three-year statute of limitations.
Does the revision apply to charges? No. Charges are adjusted annually based on actual expenses. The revision only concerns the rent excluding charges.
What if the landlord threatens to terminate the lease because I refuse the increase? Refusing an irregular increase does not constitute grounds for termination. If the landlord initiates proceedings, the judge will verify the validity of the clause and the calculation.
Sources
- Logement
- Loi n° 89-462 du 6 juillet 1989 tendant à améliorer les rapports locatifs
- Service-Public – Rédaction du bail d’habitation (contrat de location)
- Service-Public – Dépôt de garantie dans un bail d’habitation
- Service-Public – Préavis et formalités du congé donné par le locataire
- Service-Public – Charges à payer par le locataire
- Service-Public – État des lieux d’entrée dans un bail d’habitation
- ANIL – Bail location vide : montant et durée du contrat bail de location
Legal Information
The information presented on this page is provided for informational purposes and is based on the texts and sources available at the time of its publication or last update. Legislation, regulations, and case law may evolve at any time. The results and explanations offered by bail.immo do not constitute legal advice and do not replace the opinion of a lawyer or another competent legal professional.