>25%
Threshold: indexed rent must have moved by more than 25% of the last contractually or judicially fixed rent to trigger Art. L. 145-39
Either party
Works symmetrically — tenant invokes when indexed rent has risen above market; landlord invokes when market has moved above indexed rent
No floor/ceiling
Result is market value with no statutory floor and no statutory ceiling — unlike the statutory 3-year review under Art. L. 145-38
3 years
The right can be exercised within 3 years of the threshold being crossed — but the window closes if the index reverses below 25%

What Article L. 145-39 Does and Why It Matters

An indexation clause adjusts the rent automatically by reference to an index. Over several years of strong index movement, it can push the rent significantly above — or below — what the market would support. Article L. 145-39 of the Code de commerce is the statutory corrective mechanism: where the indexed rent has moved by more than 25% compared to the last contractually or judicially fixed rent, either party can demand that the rent be reset to market value (valeur locative).

Article L. 145-39 is of mandatory application. The right to invoke it cannot be waived in the lease: a clause purporting to exclude it, or to prevent the tenant from seeking a market value below the contractual rent, is unwritten (Cass. 3e civ., 6 October 2016; Cass. 3e civ., 30 March 2017). The right can only be waived once it has actually arisen — that is, once the 25% threshold has been crossed.

The 25% Threshold: What Counts as the Base

The threshold is a variation of more than 25% in the indexed rent compared to the "price previously fixed contractually or by judicial decision" (Article L. 145-39). Getting the base right is critical.

✓ Counts as the base
  • Initial rent agreed at signature
  • Rent modified by mutual amendment that fixed a new price — including where modification resulted from an extension of the lease area
  • Rent previously revised under Arts. L. 145-38 or L. 145-39
  • The renewal rent (even where not yet judicially fixed, equals the rent at expiry of the previous lease — Cass. 3e civ., 15 Dec. 2016)
✗ Does not count as the base
  • Indexed rent resulting from prior applications of the indexation clause — indexation movements themselves are not "contractually fixed" prices (Cass. 3e civ., 23 Oct. 1961)
  • Pure area adjustment where the price per m² remained unchanged (Cass. 3e civ., 9 July 2014)
  • Property tax and service charges transferred to the tenant are not added to the rent base (Cass. 3e civ., 3 May 2012)
  • Key money characterised as a compensatory indemnity is not added to the rent base (CA Paris, 27 Feb. 2013)
⚠️
Warning — The Window Can Close

The right must be exercised while the indexed rent remains above (or below) the 25% threshold. The right exists for three years after the threshold is crossed (Cass. 3e civ., 22 November 1989) — but if the index subsequently reverses and the variation falls back below 25%, the window for that particular crossing closes. Some tenants in early 2009 lost this opportunity: the ILC had been above the 25% threshold in 2007–2008, then fell back below it before they served notice. A landlord who does not apply the indexation cannot block the tenant's right: automaticity means the variation occurs regardless of whether the landlord has been collecting the indexed amounts.

Procedure: Form, Notice, and the Result

The procedural rules mirror the statutory three-year review. The notice must be served by registered letter with acknowledgment of receipt or by bailiff's act. It must state a specific rent figure, on pain of nullity (Art. R. 145-20). The revised rent takes effect from the date of the notice — not retroactively. If the parties cannot agree, the commercial rent judge fixes the rent at market value under Article R. 145-22. The commercial rent judge who fixes the revised rent below the amount the tenant has been paying also has jurisdiction to order the landlord to repay the overpayment, since that claim is accessory to the main claim (Cass. 3e civ., 17 September 2020).

Result: Market Value with No Floor or Ceiling

Under Article R. 145-22, the court "adapts the operation of the indexation clause to the rental market value at the date of the claim." The double-limit constraint that applies to the statutory three-year review (reviewed rent cannot go below current rent or above the cap) does not apply. A tenant who successfully invokes Article L. 145-39 can obtain a rent below the level at which indexation has arrived, and even below the original contractual rent. Where the resulting increase is above market value, the Pinel Act caps the annual increase at 10% of the rent paid in the preceding year — the same plafonnement du déplafonnement that applies to uncapped statutory reviews.

💡
Practical Point — No Uncapping at Renewal from Art. L. 145-39 Revision

A revision of the indexed rent under Article L. 145-39 is not a "notable modification of the parties' obligations" and therefore does not constitute a ground for uncapping the renewal rent at the end of the lease (Cass. 3e civ., 11 April 2019). Tenants who successfully reduce the indexed rent mid-lease do not create the risk that the landlord will argue for an uncapped renewal at expiry on the basis that the indexed rent revision was a notable change.

Coexistence with the Statutory Three-Year Review

Both Article L. 145-38 (statutory three-year review) and Article L. 145-39 (indexed rent review) can potentially apply to the same lease at the same time. Art. L. 145-39 is a special provision that prevails over Art. L. 145-38 as the general rule. A landlord cannot pre-empt a tenant's Art. L. 145-39 claim by first serving a three-year review notice under Art. L. 145-38 — the "price previously fixed contractually or by judicial decision" for the purposes of the 25% calculation is not the unresolved Art. L. 145-38 claim (TGI Paris, 13 November 2009).

Point of comparisonArt. L. 145-38 (3-year review)Art. L. 145-39 (indexed rent review)
Trigger3-year waiting period from last fixation; no 25% threshold needed25% threshold crossed; no minimum waiting period
ResultMarket value subject to double-limit constraint (floor = current rent; ceiling = cap)Market value with no floor and no ceiling
Proof requiredMaterial change in local trading conditions to break the capOnly proof of the 25% variation
Priority where both availableGeneral rule — displaced by Art. L. 145-39Special provision — prevails over Art. L. 145-38
Indexed Rent Review Checklist
  • Monitor against the last contractually fixed rent: not against the progressive result of prior indexation steps. Alert when cumulative variation approaches 25%. The right exists for 3 years from crossing but may be lost if the index reverses before you act (Cass. 3e civ., 22 Nov. 1989).
  • Base calculation (Art. L. 145-39): counts — initial rent, amendments fixing a new price, prior revisions, renewal rent. Does not count — prior indexation movements, area adjustments at same price/m², property tax, service charges, compensatory key money.
  • Notice requirements: registered letter (LRAR) or bailiff's act; specific figure required on pain of nullity (Art. R. 145-20); new rent effective only from date of notice. Court can also order repayment of overpaid rent as an accessory claim (Cass. 3e civ., 17 Sept. 2020).
  • Result — no floor or ceiling (Art. R. 145-22): pure market value; Pinel 10% annual cap applies on upward revisions. Not a "notable modification" — no uncapping at renewal (Cass. 3e civ., 11 Apr. 2019). Right cannot be waived in the lease — only waivable once the 25% has been crossed.
  • Art. L. 145-39 prevails over Art. L. 145-38 as the special provision. Landlord cannot block the tenant's Art. L. 145-39 claim by first serving a 3-year review notice. Landlord inaction (not applying the indexation) does not waive the right or block the tenant from invoking the 25% variation.
Dealing with an Indexed Rent That Has Drifted Far From Market?

Whether the indexed rent is now above or below market value, we can assess whether the Article L. 145-39 threshold has been reached and advise on the procedure, timing, and strategy for seeking a reset to market value — including whether to invoke Article L. 145-39 or the statutory three-year review, or both.

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This article is for general information and educational purposes only. It does not constitute legal advice and does not create a lawyer-client relationship. Laws and regulations may have changed since publication. Always seek qualified French legal advice before invoking or defending against an indexed rent review.