Indexation of Commercial Rents: Beware the Calculation of the Review Threshold

Imagine: you own a commercial property in Saint-Vincent-de-Tyrosse, leased to a ready-to-wear chain. The lease provides for an annual indexation of the rent based on the construction cost index (ICC). For three years, you diligently apply the indexation and your tenant pays the indexed rent without complaint. But when the Bail commercial : l'engagement solidaire des copreneurs">three-year review comes around, you notice that the rent has increased by 15% compared to the initial rent. You think: "this is the time to revise the rent to the market rental value, given the soaring prices in the area." But beware: the law sets a threshold that must not be exceeded in order to request a review. And this threshold is not necessarily calculated as you might think. The French Supreme Court ruled in a judgment of 15 December 2016 (No. 15-27.148): to check whether the indexed rent has increased by at least 10% compared to the initial rent, the rent resulting from the application of the indexation clause must be compared to the price previously fixed by the parties' agreement, excluding indexation, and not the rent actually paid. In other words, any indexation errors or voluntary overpayments are disregarded. This distinction is crucial for any landlord or tenant of a commercial lease.

The Facts: A Story That Happens Every Day

The case concerns a commercial lease for premises situated... in the Paris region, but the reasoning applies to all commercial leases in France, including within the jurisdiction of Mont-de-Marsan. Mr. X, the owner, and company Y, the tenant, signed a lease in 1997 with an initial annual rent of €8,141,844.91 (a high amount, but the principle is the same for a rent of €10,000). In 2007, they signed an amendment fixing the rent at the same amount from 1 January 2007. The lease provides for annual indexation based on the ICC. For several years, the tenant pays an indexed rent, but in reality, the indexation clause is applied irregularly: the base index is incorrect, and the rent paid exceeds what a correct application of the clause would have produced. In 2010, the owner considers that the rent has increased by more than 10% compared to the initial rent (due to successive indexations) and requests a revision of the rent to the market rental value (i.e., an updated rent based on market conditions). The tenant contests this: according to him, the increase does not reach the 10% threshold because the initial rent must be compared with the rent actually paid, which is higher than the rent resulting from a regular indexation. The trial court rules in favour of the owner, but the court of appeal overturns that decision. The owner appeals to the Supreme Court. The question put to the Supreme Court is therefore: which rent should be taken into account to assess the three-year review threshold? The rent actually paid, or the rent that would result from a correct application of the indexation clause?

The Reasoning of the Court — Analysed

The French Supreme Court, in its judgment of 15 December 2016, quashes the court of appeal's decision and rules in favour of the owner. Why? Because Article L. 145-39 of the Commercial Code (which allows the three-year review of the rent when the initial rent has varied by more than 10% due to indexation) must be strictly interpreted. The text says: "Where the rent has been revised in application of indexation clauses, a request for revision may be made upon expiry of a period of three years from the date of commencement of the lease or the last contractual revision, if the variation in the reference index has resulted in a change in the rent of at least 10% compared to the price previously fixed by the parties' agreement." The Court specifies that the "price previously fixed by the parties' agreement" is the initial rent or the last rent contractually revised (excluding indexation). And the "rent obtained through the operation of the indexation clause" is the rent resulting from the regular application of that clause, i.e., using the indices provided for in the contract. It does not matter that the tenant paid a higher rent (by mistake or generosity): what matters is the mathematical rent resulting from the indexation. In short, if the regular indexation gives a rent of €8,952,000 (i.e., +10% compared to the initial rent of €8,141,844.91), the threshold is crossed, even if the tenant paid €9,000,000. This solution is logical: the tenant should not be able to rely on his own payment errors to block the review. However, beware: if the landlord applied an erroneous indexation, the tenant may claim a refund of overpayments. undefined, I have encountered cases where a landlord in Capbreton had indexed the rent on an obsolete index, artificially inflating the rent. The tenant paid for years without checking. At the time of the review, the landlord wanted to increase the rent, but the tenant was able to argue that the indexation was irregular and that the threshold had not been reached. Result: the landlord had to refund the overpayments and could not revise the rent. This Supreme Court decision therefore confirms a technical approach: the calculation of the threshold is a matter of law, not fact.

What This Means for You — Practically

For landlords: you must absolutely ensure that the indexation clause in your lease is properly drafted and applied. If you wish to trigger a three-year review, calculate the indexed rent in accordance with the contract (using the correct base and reference indices). If this indexed rent is at least 10% higher than the last rent fixed by the parties' agreement (excluding indexation), you can request a revision to the market rental value. Concrete example: initial rent €10,000, base index 100, reference index 112, giving an indexed rent of €11,200. The increase is 12%, so the threshold is crossed. You can request an updated rent, e.g., €12,000 if the market rental value is higher. For tenants: if the landlord applies an erroneous indexation (wrong index, wrong period), you can contest the rent paid and claim a refund of overpayments (limitation period: 5 years). But beware: you cannot oppose the review by arguing that you paid more than the regular indexation. For purchasers of commercial premises: during due diligence, check the history of indexations and reviews. A calculation error can have significant financial consequences. For real estate professionals (agents, property managers): train yourselves in these subtleties. A simple index error can cost your client thousands of euros.

Four Tips to Avoid This Type of Dispute

• Check the indexation clause upon signing the lease: ensure it mentions the reference index (ICC, ILAT, ILC...), the frequency (annual, quarterly) and the base date. Example: "The rent shall be revised each year on the anniversary date of the lease, based on the variation of the construction cost index (ICC) published by INSEE, the base index being that of the first quarter 2020."
• Apply the indexation rigorously each year: use the correct index, the correct formula (initial rent × new index / base index). Do not simply take the previous year's rent and apply an approximate percentage.
• Keep all calculations and supporting documents: retain a record of the indices used, calculations, and rent receipts. In the event of a dispute, you will be able to prove the regular indexed rent.
• For landlords: before triggering a three-year review, have the threshold calculated by a professional: a lawyer or accountant. A threshold error may cause you to lose the opportunity to revise for an additional three years.

Further Reading: Related Case Law and Developments

This Supreme Court decision is consistent with a steady line of authority: it reminds us that the three-year review mechanism is a matter of public policy (it cannot be contracted out of) and that its triggering is strictly regulated. In an earlier judgment of 20 January 2016 (No. 14-26.778), the Court had already held that to assess the threshold, the initial rent must be compared with the rent resulting from indexation, and not with the rent actually paid. The 2016 judgment confirms and clarifies this solution. The courts are therefore very attached to a literal application of Article L. 145-39. However, beware: the Pinel Law of 2014 amended the reference indices (ILC, ILAT) and the revision procedures for leases entered into after 1 September 2014. But for earlier leases, the rules remain those of the 2016 judgment. What few people know is that the 10% threshold is assessed over the three-year period, but if indexation has been omitted for one or more years, the calculation is made by cumulating the missed indexations. A real headache!

Frequently Asked Questions

• Q: How do I calculate the regular indexed rent?
  A: Use the formula: Initial rent × (reference index / base index). Example: initial rent €10,000, base index 100 (Q1 2015), reference index 110 (Q1 2018), indexed rent = €11,000.
• Q: What should I do if the landlord has applied an erroneous indexation?
  A: The tenant can claim a refund of overpayments for the last 5 years (limitation period). They can also contest the three-year review if the threshold is not reached with the regular indexation.
• Q: Can I revise the rent every 3 years even without indexation?
  A: Yes, but not automatically. The three-year review is available at any time after each 3-year period, but it requires demonstrating a material change in local commercial factors (Article L. 145-38). Indexation is a special case that allows a review without having to prove such a change.
• Q: What is the deadline for requesting a review after the threshold is crossed?
  A: You can request a review at any time after the expiry of the 3-year period, even if the threshold was crossed earlier. But beware: if you wait too long, the five-year limitation period may apply to any overpaid rents.
• Q: Does this decision apply to residential leases?
  A: No, it concerns only commercial leases (Commercial Code). Residential leases have their own rules (1989 Act).

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