You have just received a letter from your landlord: "As of October 1, your rent will increase to €712, in accordance with the rent review clause in your lease." You reread the contract, look for the index, redo the calculation three times... and you are not sure it is correct. Good news: rent review is not a unilateral decision by the landlord. It follows precise rules, and a poorly drafted clause may simply be unenforceable.
Before paying, take ten minutes to check three things: Does the clause actually exist? Is the correct index being used? Is the review date respected? If any of these conditions are missing, you can refuse the increase.
The Answer in 30 Seconds
Rent review during a lease is only possible if the contract contains a clause that explicitly provides for it. This clause must specify the review date, the reference rent index (IRL), and the calculation formula. Without a clause, there is no review. If the clause exists, the landlord must apply the IRL from the same quarter as the lease signing, and only on the anniversary date. A missed review is lost: the landlord cannot recover past years. Finally, if the increase seems irregular, you can contest it, first by letter, then before the judge for protection disputes.
Want to know if your lease clause is solid? Upload your contract to bail.immo and get a clear analysis of the risk points.
What the Law Says
Rent review is governed by the law of July 6, 1989, particularly Article 17-1. The principle is simple: the rent for a property rented unfurnished or furnished as a primary residence can be reviewed annually, but only if the lease provides for it. The law does not create an automatic right to review. It is the clause that opens this possibility.
The review is carried out by applying the variation in the reference rent index (IRL), published quarterly by INSEE. The formula is as follows:
New rent = current rent × (IRL of the reference quarter / IRL of the same quarter of the previous year)
The IRL to use is the one for the quarter corresponding to the lease signing date. For example, if you signed in March, you use the IRL for the 1st quarter. If you signed in September, the IRL for the 3rd quarter. The landlord cannot choose another quarter, even if the index is more favorable to them.
The review can only occur once a year, on the anniversary date of the lease. If the landlord forgets to review one year, they cannot retroactively claim unapplied increases. The review takes effect on the date of the request, not before.
Note: The review does not apply to charges. Utility and service charge provisions evolve according to actual expenses, not the IRL. If your landlord increases charges at the same time as the rent, ask for the breakdown.
Why This Can Be Problematic
In practice, disputes rarely arise from the principle of review, but from its application. Here are the most common situations.
The clause is absent or too vague. Some leases simply mention "the rent will be reviewed annually according to the law." This wording is insufficient. The clause must specify the review date and the reference index. Without these elements, the review is unenforceable.
The wrong IRL is used. A landlord may apply the IRL for the 4th quarter when the lease was signed in the 2nd quarter. The difference may seem minor, but over several years, it widens. Always check the quarter.
The review is applied late. The landlord sends a letter in November to review a rent whose anniversary date was in March. They cannot demand retroactive payment for the months that have passed. The increase only applies going forward.
The clause provides for indexing on another index. Some contracts mention the construction cost index (ICC) or a commercial index. For a residential lease, this is illegal. Only the IRL is allowed. Such a clause is deemed unwritten.
The rent is reviewed during a mobility lease. A mobility lease, lasting 1 to 10 months, cannot be reviewed. Any review clause is prohibited. If your mobility lease contains one, it is void.
Let's take a concrete example. You signed a lease on April 15, 2024, with a rent of €800 excluding charges. The clause provides for an annual review on the anniversary date. In April 2025, the landlord announces a new rent of €832. You check: the IRL for the 1st quarter of 2024 was 143.50, and for the 1st quarter of 2025 it is 146.80. The calculation gives: 800 × (146.80 / 143.50) = €818.40. The announced increase is too high. You refuse and ask for the calculation details.
Another case: your lease contains no review clause. In June, the landlord writes to increase the rent by 3%. You do not have to pay. The law does not allow rent review without a clause. The landlord will have to wait until the lease renewal to attempt a reassessment, under the conditions provided by law.
Exceptions to Know
Not all leases are the same. Here are the main distinctions.
Unfurnished or furnished lease. Review is possible in both cases, provided the clause exists. The rules are identical.
Mobility lease. No review is possible, regardless of the clause. The rent is fixed for the entire duration of the lease.
Social housing. Rents for HLM housing follow specific rules set by the housing organizations. The review does not follow the same mechanism.
Tension zones and rent control. In Paris, Lille, Lyon, Villeurbanne, Bordeaux, or municipalities subject to rent control, the review cannot lead to exceeding the increased reference rent. If the revised rent exceeds this cap, the tenant can contest it.
Leases signed before March 27, 2014. The review rules were modified by the ALUR law. For older leases, the clause may provide for another index, but since that date, the IRL applies to all residential leases.
Checklist: Verify a Rent Review
Before accepting an increase, go through these points.
- Does the lease contain an explicit review clause?
- Does the clause specify the review date and the IRL?
- Does the IRL used correspond to the quarter of the lease signing?
- Does the review occur on the anniversary date, not before?
- Is the calculation correct: current rent × (new IRL / old IRL)?
- Does the increase only apply to future rents, not past months?
- Is the lease a mobility lease (in which case, no review)?
- Does the revised rent comply with rent control if you are in a tension zone?
If any box remains unchecked, do not pay the increase without verification. A registered letter to the landlord is often enough to clarify the situation.
Possible Actions in Case of Irregular Review
You think the review is abusive? Here is the procedure to follow.
- Ask for the calculation details. The landlord must be able to justify the index used and the formula applied. A simple letter or email may suffice.
- Send a written contestation. If the calculation is wrong or the clause is absent, write to the landlord by registered mail with return receipt. Remind them of the legal texts and request the cancellation of the increase.
- Refer the matter to the departmental conciliation commission. This step is free and often quick. It can help reach an agreement without going to court.
- Refer the matter to the judge for protection disputes. As a last resort, the judge can cancel the review, order the landlord to reimburse overpaid amounts, and possibly award damages.
The deadline to act is three years from the day you became aware of the irregular review. Do not let this deadline pass.
Not sure about the validity of the clause? Have your lease analyzed on bail.immo before starting a procedure.
FAQ
Can my landlord review the rent without a clause in the lease? No. The annual review is only possible if the lease contains an explicit clause. Without a clause, the rent remains unchanged until the lease renewal.
Which IRL should be used for the calculation? The IRL for the quarter corresponding to the lease signing date. If you signed in February, it is the IRL for the 1st quarter. If you signed in August, it is the IRL for the 3rd quarter.
Can the landlord catch up on a missed review? No. A review not applied in a given year is lost. The landlord cannot retroactively claim increases from previous years.
Does the review apply to charges? No. Charges evolve according to actual expenses, not the IRL. An increase in charges must be justified by a breakdown.
What to do if the landlord applies the wrong index? Refuse the increase by registered letter and ask for the calculation with the correct IRL. If the disagreement persists, refer the matter to the conciliation commission or the judge.
Can a mobility lease provide for a review? No. A mobility lease is concluded for a short duration and its rent cannot be reviewed. Any review clause is void.
Sources
- Service-Public – Security deposit in a residential lease
- Légifrance – Law No. 89-462 of July 6, 1989
- Service-Public – Notice period and formalities for tenant's notice to quit
- Service-Public – Charges payable by the tenant
- Service-Public – Inventory of fixtures at the start of a residential lease
- Service-Public – Drafting a residential lease
- Service-Public – Housing
- ANIL – Unfurnished rental lease: amount and duration of the contract
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.