The annual rent revision is one of the most contentious issues between landlords and tenants. On one side, the owner wants to preserve the profitability of their property in the face of inflation. On the other, the tenant fears an increase that is miscalculated, applied at the wrong time, or worse, without any legal basis.
This guide reviews the rules applicable to residential leases governed by the loi du 6 juillet 1989. You will learn whether the clause in your lease is valid, how to check the calculation, and what to do if the revision seems irregular.
The answer in 30 seconds
A rent revision during the lease is only possible if the contract contains an express revision clause. It takes place once a year, on the anniversary date of the lease or on a date specified in the clause. The new rent is calculated using the Indice de Référence des Loyers (IRL) published quarterly by INSEE.
If the landlord fails to apply the revision on the scheduled date, they cannot apply it retroactively. They may only apply the revision for the current year, with no effect on months already elapsed. And if the clause is missing or poorly drafted, no revision is possible for the entire duration of the lease.
Need to check your situation? Analyze your lease in a few minutes to identify risky clauses, including the revision clause.
What the law says
Article 17-1 of loi n° 89-462 du 6 juillet 1989 strictly regulates rent revision during the lease. The principle is simple: no clause, no revision. If the contract does not explicitly mention the possibility of revising the rent, the amount remains frozen until the end of the lease, regardless of how the IRL evolves.
The clause must specify:
- the frequency of the revision (in practice, annual);
- the date on which it takes effect (anniversary date of the lease or another agreed date);
- the reference index used (the IRL, or failing that, a replacement index provided for by law).
The revision applies automatically, without the need for an addendum. The landlord does not need the tenant's consent, but must strictly comply with the formal and timing requirements.
The Indice de Référence des Loyers (IRL)
The IRL is published quarterly by INSEE. It corresponds to the average, over the previous twelve months, of the change in consumer prices excluding tobacco and excluding rents. It has been the reference index for residential leases since the loi du 8 février 2008.
The revision is calculated as follows:
New rent = current rent × (IRL for the reference quarter / IRL for the same quarter of the previous year)
The IRL to use is that of the most recent quarter known at the revision date. For example, for a revision on October 1, 2026, the IRL for Q2 2026 (published in July 2026) is used, compared with the IRL for Q2 2025.
The cap on the increase
The revision cannot result in an increase greater than the year-over-year change in the IRL. If the clause provides for a formula more favorable to the landlord (for example, indexation to a more volatile index or a flat-rate increase), it is deemed unwritten. The rent remains revisable, but only according to the IRL.
Why this can cause problems
Disputes over rent revision rarely stem from malicious intent. Most often, it is a lack of knowledge of the formal requirements that creates the conflict.
The forgotten or poorly drafted clause
A standard lease downloaded from the internet may contain an incomplete revision clause. If it does not specify the revision date, or if it refers to an index that no longer exists (such as the ICC, the construction cost index, for a residential lease), the clause is inapplicable. The landlord believes they can revise, the tenant disputes it, and the judge decides: no revision.
The revision applied late
This is the most common case. The landlord wakes up in March for a revision that should have taken place in January. They then send a letter requesting the new rent with retroactive effect to January 1. This is illegal. The revision can only take effect for the future, from the date of the landlord's request. January and February remain due at the previous rent.
The miscalculation
An error in the index, an inversion in the formula, an approximate rounding… There are many sources of error. A miscalculation in the landlord's favor can represent several dozen euros per month, or several hundred euros per year. A tenant who pays without checking loses money, and a landlord who makes a mistake exposes themselves to a dispute.
The absence of notification
The revision is not automatic in practice. The landlord must express their intention to apply it, generally by letter or email to the tenant. If they do not, the rent remains unchanged. And if they do so late, the revision only applies for the future.
Concrete example
Take a lease signed on September 15, 2024, with a monthly rent of €800 excluding charges. The clause provides for an annual revision on the anniversary date, i.e. September 15 of each year.
On September 15, 2026, the landlord wishes to revise the rent. The IRL for Q2 2026 (most recently published) is 145.20. The IRL for Q2 2025 was 141.80.
Calculation: 800 × (145.20 / 141.80) = €819.18.
The new rent is €819.18, an increase of €19.18 per month. This increase corresponds exactly to the year-over-year change in the IRL (2.4%).
If the landlord had applied a different index or a flat-rate increase of 3%, the clause would be deemed unwritten and the rent could only be revised according to the IRL.
Exceptions to know
Leases subject to a different regime
The rules of article 17-1 of the 1989 law apply to primary residence leases (unfurnished or furnished rentals). They do not apply to:
- seasonal rentals;
- mobilité leases (subject to specific rules, with no revision possible during the lease);
- mixed-use rentals (professional and residential);
- commercial leases, which are governed by a different indexation regime.
High-demand areas and rent control
In municipalities subject to rent control (Paris, Lille, Lyon, Villeurbanne, Bordeaux, Montpellier, etc.), the revision cannot result in a rent higher than the increased reference rent set by prefectoral order. If the revised rent exceeds this ceiling, the tenant can dispute it and request a reduction.
Leases signed before the ALUR law
For leases signed before March 27, 2014, the revision clause may refer to the ICC (construction cost index). The ALUR law replaced the ICC with the IRL for residential leases, but earlier clauses remain valid if they provided for the ICC. In that case, the revision is made according to the ICC, unless the parties agree to switch to the IRL.
Checklist: verifying a rent revision
- The lease contains an express revision clause (a dedicated article, not just a vague mention).
- The clause specifies the revision date (anniversary date or another date).
- The index mentioned is the IRL (or the ICC for leases predating 2014).
- The calculation uses the correct quarter of the IRL (most recently published at the revision date).
- The formula is correct: rent × (new IRL / old IRL).
- The increase does not exceed the year-over-year change in the IRL.
- The landlord has notified the tenant of the revision (letter, email, etc.).
- The revision is not applied retroactively.
- The revised rent complies with rent control if the municipality is concerned.
Unsure whether the clause is valid? Check your lease with our analysis tool.
Possible actions in the event of a dispute
For the tenant
If you believe the revision is irregular:
- Do not stop paying the rent, even if you dispute the increase. Continue paying the previous rent and set aside the difference if necessary.
- Write to the landlord by registered letter with acknowledgment of receipt, explaining precisely why the revision seems irregular to you (missing clause, wrong index, miscalculation, delay).
- Refer the matter to the departmental conciliation commission (CDC) if the disagreement persists. It is free and often faster than a lawsuit.
- As a last resort, bring the matter before the juge des contentieux de la protection of the judicial court. The limitation period is 3 years from the day you became aware of the disputed revision.
For the landlord
If you wish to apply a revision:
- Check the clause in your lease before taking any action. If it is missing or incomplete, do not claim anything: you would lose in the event of a dispute.
- Calculate precisely the new rent using the correct IRL. A calculation error can justify a refusal by the tenant.
- Notify the revision in writing, indicating the detailed calculation and the effective date.
- Respect the anniversary date. If you are late, do not apply the revision retroactively.
FAQ
Is the rent revision automatic?
No. The revision clause makes the revision possible, but it only applies if the landlord requests it. Without notification, the rent remains unchanged.
Can the landlord revise the rent twice in the same year?
No. The revision is annual. Only one revision per twelve-month period is possible, even if the clause provides for a different frequency.
What happens if the IRL is not published by the revision date?
The most recently published IRL before the revision date is used. If the IRL were to disappear, the law provides for a replacement index (generally the consumer price index excluding tobacco).
Does the revision apply to charges?
No. The revision only concerns the rent excluding charges. Charges are settled separately, with supporting documents.
Can a tenant dispute a revision they have already paid?
Yes, within the 3-year limitation period. If you have paid an irregular revision, you can request reimbursement of the overpayment for the last three years.
Sources
- Loi n° 89-462 du 6 juillet 1989 tendant à améliorer les rapports locatifs, article 17-1
- Indice de référence des loyers (IRL) – INSEE
- Service-public.fr – Révision du loyer en cours de bail
- ANIL – La révision du loyer en cours de bail
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 change 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 qualified legal professional.