IRL Index & Rent Review 2026: The Official Calculation Guide

What to remember: rent revision in 2026 strictly according to the Rent Reference Index (IRL) of INSEE. This legal basis allowsupdating the lease amount via the official calculation formula, subject to a valid clause. As an indication, the index for the 4th quarter 2025 was 145.78, an annual change of +0.79 %.

Are you afraid of an adverse calculation error when applying the rent revision for 2026? This guide gives you the official indices of INSEE and the exact formula for adjust your rental income in full compliance. Master the legal rules to secure your increase without any risk of litigation.

The latest IRL indices to know for 2026

Reference values published by INSEE

The Rent Reference Index (IRL) is the only legal basis to review your rents. Published quarterly by INSEE, it monitors the evolution of consumer prices, excluding tobacco and rents.

For 2026, use the official indices below. These figures from the Official Journal are essential to guarantee the validity of your calculations and avoid any dispute.

The table of indices for your calculation

This table presents the last four indices required for your rent review. Note that values change according to the location of the dwelling.

The reference quarter is that indicated in the lease. If not, take the last published index on the date of signature of the contract.

The official formula to calculate your new rent

Now that you have the clues, let's see how to use them concretely for determine the amount of the increase.

Apply the revision formula step by step

To validate a irl rent revision and avoid any subsequent litigation, the rigour is necessary. Follow these 4 steps scrupulously to get the indisputable amount:

1. Isolate Rent Off Charges (HC):

   It's the most expensive mistake. Never take the total amount of the transfer. You should use only bare rent, without provisions for expenses.

2. Identify the corresponding indices:

   Recover it « New IRL » (this is the quarter of the current year) and « Former IRL » (that of Same the previous year).

3. Apply the official formula:

   Place the following operation: New Rent = Rent HC x (New IRL / Former IRL)

4. Round the result:

   The amount obtained often has several digits after the comma. The tax rule is rounding down to two decimal places (e.g. 806.324 becomes 806.32 €).

Une bonne financial management begins with precise calculations.

Concrete example of calculation for a lessor

Take Mr. Martin's example. He rents an apartment in the metropolis for a rent of 800 € Other charges. The lease was signed in the 4th quarter and the revision takes place on this anniversary date.

The calculation will be: 800 € x (IRL T4 2025 / IRL T4 2024). Either: 800 x (145.78 / 144.64) = 806.32 €. The new rent will be 806.32 €. Note that the result must be rounded to two decimal places.

The 3 legal conditions to be able to revise the rent

The revision clause: a mandatory mention in the lease

This is the golden rule: without writing, no increase is allowed. Your contract must contain an unambiguous annual review clause. If it is missing, the rent remains fixed forever.

The reference quarter must be black on white. Otherwise, the last known index at the signature applies. It's a classic mistake when you want investing in rental real estate. Be very vigilant on this specific point.

Legal safeguards not to be ignored

Having the clause is not enough. Two major obstacles exist.

Here are the strict limits your calculation irl révision loyer :

• The requirement of one year : The lessor shall have one year from the date scheduled to claim his dues. After this period, the increase is lost (Act ALUR). The application is never retroactive.
• The prohibition for thermal colanders: Since the Climate and Resilience Law, to increase housing classified as F or G to the DPE is illegal. This measure affects all leases, signed or renewed.

IRL: publication and related indices

Finally, Some practical points on the IRL calendar and other clues you might encounter.

The publication schedule of the index

INSEE publishesIRL quarterly to regulate the rental market. This official data generally falls around the 15th of the month following the end of the period concerned. Note this recurring deadline.

Let us take a concrete example to illustrate mechanics. The index of the 4th quarter 2025 thus comes out mid-January 2026. The date of publication in the Official Journal officializes the value to be used. It's the only figure effective against tenant.

Do not confuse IRL, ILC and ILT

Other indices exist in the rental market. Yet they never concern your residential units.

Confusion costs a lot when an irl rent revision is poorly targeted. The following are the strict distinctions to be respected in order to guarantee legal validity of your leases :

• IRL (Rent Reference Index): This is the only single index for residential leases (empty or furnished housing).
• ILC (Commercial Rent Index) : It applies to commercial and craft leases.
• (Indice of Rents of Tertiary Activities) : It covers other activities, such as offices or warehouses.

The rent revision for 2026 is based on the strict application of the INSEE indices and compliance with legal constraints, including the DPE. By following the official form and time limits, you secure your rental income while maintaining a transparent relationship with your tenant. The compliance remains your best asset.

FAQ

What is the IRL index table for 2025?

To perform your review calculations in 2025, you must refer to the quarterly values officially published by INSEE. The indices to be used are as follows: 145.47 for the 1st quarter (+1.40), 146.68 for the 2nd quarter (+1.04 %), 145.77 for the 3rd quarter (+0.87%) and 145.78 for the 4th quarter (+0.79 %).

How do you calculate your rent increase in 2025?

You must apply the following legal formula: Rent without charges x (New IRL / Old IRL). In concrete terms, you multiply the amount of your current rent by the index of the reference quarter of 2025, then divide the result by the index of the same quarter of the year 2024. The result obtained corresponds to your new rent revised.

What is the legal increase allowed for rents in 2025?

The legal increase corresponds exactly to the percentage change in IRL between year N and year N-1. For 2025, this increase was contained, starting at 1.40 % in the first quarter and gradually falling to +0.79% at the end of the year. You can't under any circumstances. apply an increase above this official annual change.

What IRL index should you use for a revision in July 2025?

If your lease review date is set in July, you usually have to use 2nd quarter 2025 index, which is the last index published on that date (mid-July publication). The value of this index is 146.68, an increase of 1.04 % over the previous year.

How do you check if your rent increase is fair?

You must proceed in order of priority. First, make sure your lease contains an annual review clause: without it, the rent does not move.

Then check the energy class of housing (DPE):

⛔ IMPORTANT: If your accommodation is classified as F or G (thermal pass), any rent increase is strictly prohibited by law (Climate & Resilience Law), regardless of what the lease says.

If these lights are green, then you can check the mathematical calculation using the official INSEE indices for the quarter of your contract.