Irrebuttable
Once a competition authority decision establishing the infringement is no longer challengeable, the practice is deemed irrebuttably established — the class action court cannot revisit the finding of infringement.
5 years
Limitation period for the antitrust class action: from the date the decision establishing the infringement is no longer susceptible to any challenge on its merits.
Parallel
Where an appeal of the competition decision does not challenge the finding of infringement itself — only the sanction or procedure — the class action can proceed in parallel with that appeal.

Why the Antitrust Class Action Is a Distinct Track

The standard consumer class action tasks the court hearing the class action with finding the professional's liability from scratch, on the basis of the individual cases the association presents. The antitrust class action is structurally different: it does not ask the court to establish liability. By the time the class action is filed, liability has already been determined — by a competition authority or court decision that is no longer open to challenge on the merits. The role of the class action court is therefore not to re-examine whether an infringement occurred, but to determine what individual harm that already-established infringement caused to consumers, and how they should be compensated.

This architecture is the defining feature of the action de groupe « concurrence », and it explains several of the specific rules that differ from the standard track: the irrebuttable presumption, the five-year limitation period running from the exhaustion of challenges, and the possibility of provisional execution of consumer information measures before the class action judgment is final.

The Prerequisite: A Prior Final Competition Decision

The court hearing the antitrust class action can find the professional liable only on the basis of a decision by a competent French or European authority or court establishing the anticompetitive practice, provided that decision is no longer susceptible to any challenge for the part relating to the establishment of the practice (Art. L 623-24 C. consom.).

Once that threshold is met, the finding of infringement is deemed irrebuttably established (réputée établie de manière irréfragable) (Art. L 481-2 C. com.). The defendant cannot re-argue before the class action court that the infringement did not occur, that the analysis was wrong, or that the authority misapplied the law. The liability finding is treated as a proven fact.

Which Decisions Qualify

Qualifying Decisions and Their Sources
French authority The Autorité de la concurrence — a final decision finding an infringement of Arts. L 420-1 (cartels), L 420-2 (abuse of dominance or economic dependence), or L 420-5 (predatory pricing) of the Code de commerce, no longer subject to appeal before the administrative courts or the Cour de cassation for the part relating to the infringement finding itself.
French court A French court decision (including a court of appeal or the Cour de cassation) establishing an anticompetitive infringement under the same provisions, no longer susceptible to further challenge on the infringement finding.
EU authority The European Commission — a final decision finding an infringement of Arts. 101 or 102 of the TFEU, no longer subject to annulment proceedings before the EU courts for the part establishing the infringement.
EU court The General Court or Court of Justice of the EU — a final judgment establishing an infringement of Arts. 101 or 102 TFEU, no longer open to further challenge on the infringement finding.
Excluded Decisions relating to concentrations (mergers) (Art. L 430-1 et seq. C. com.) are expressly excluded. No action de groupe can be brought on the basis of harm resulting from an operation of concentration. The antitrust class action covers only the three specified infringement categories, not merger control outcomes.

The Three Covered Competition Law Infringements

The action de groupe « concurrence » is available in respect of the competition law violations listed in Title II of Book IV of the Code de commerce and in Arts. 101 and 102 TFEU (Art. L 623-24, al. 1 C. consom.). In practice this covers three main categories:

Practice 1 C. com. Art. L 420-1 — TFEU Art. 101 Unlawful Cartels (Ententes Illicites)

Concerted practices, agreements, and decisions by associations of undertakings that have the object or effect of preventing, restricting, or distorting competition in a market. Classic forms: price-fixing, market-sharing, bid-rigging, output restrictions. Cartels typically inflate prices across a market, causing direct financial harm to consumers who paid more than they would have in a competitive market.

Practice 2 C. com. Art. L 420-2 — TFEU Art. 102 Abuse of Dominant Position

The abusive exploitation of a dominant position in a market, or of a state of economic dependence. Relevant abuses include predatory practices, exclusionary discounts, refusal to deal, and tying. Also covers abuse of a state of economic dependence even in the absence of a dominant position in a market.

Practice 3 C. com. Art. L 420-5 Abusively Low Pricing (Prix Abusivement Bas)

Offering prices to final consumers so abusively low that they are below the cost of production, processing, and marketing. This practice aims to drive competitors from the market and ultimately harms consumers by reducing market competition. Note: this is a French national provision with no direct EU equivalent under Arts. 101/102 TFEU.

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Concentrations Are Explicitly Excluded

The antitrust class action cannot be founded on harm caused by a merger or acquisition (opération de concentration) subject to Art. L 430-1 et seq. of the Code de commerce. Even where a merger was ultimately cleared subject to remedies, or blocked, any consumer harm arising from the concentration is not actionable through the action de groupe « concurrence » track. This exclusion is explicit in Art. L 623-24.

The Irrebuttable Presumption: What It Means for Defendant Businesses

The irrebuttable presumption created by Art. L 481-2 of the Code de commerce is one of the most severe aspects of the antitrust class action for defendant businesses. Its practical consequences are:

  • No re-litigation of the infringement finding. The class action court is bound by the competition authority's or court's finding that an infringement occurred. The defendant cannot argue that the infringement was not established, was analysed incorrectly, or was of insufficient seriousness.
  • No new evidence on the infringement itself. The class action proceedings focus exclusively on the harm suffered by consumers and its quantum — not on whether the infringement happened. Evidence and expert witnesses are directed at establishing the existence and extent of the harm, not at revisiting the competition law analysis.
  • The professional's only remaining defences are on harm and causation. A defendant can still argue that the identified consumers did not in fact suffer harm, that the harm was not caused by the infringement, that the harm was passed on to commercial customers rather than end consumers, or that the harm was smaller than the association claims. These remain live factual disputes even after the infringement is established.

The Five-Year Limitation Period and When It Runs

The action de groupe « concurrence » must be brought within five years from the date on which the competition authority or court decision is no longer susceptible to any challenge (Art. L 623-25 C. consom.).

This five-year clock does not start until the relevant decision has become fully final — meaning that the period for challenging the finding of infringement (not other aspects of the decision, such as the sanction) has expired or been exhausted. This produces an important interaction with the appeal dynamics of competition decisions:

The Five-Year Limitation: How the Clock Works
Competition authority or court decision issued Finding of infringement (cartel, abuse of dominance, predatory pricing). The decision identifies the infringement, its participants, and typically the period of infringement.
Appeal period — potentially up to a decade in complex cases Exhausting challenges to an Autorité de la concurrence or Commission decision can, in certain cases, take up to ten years. However, where the challenge concerns only the sanction amount or procedural aspects — not the finding of infringement itself — the five-year clock for the class action may start before the appeals are fully concluded.
Decision final on the infringement finding The finding of infringement is no longer susceptible to challenge (even if the sanction or procedural aspects are still being appealed). Five-year limitation period for the class action begins from this date (Art. L 623-25).
Deadline: 5 years later Association must have filed the action de groupe summons before this date. Once this window closes, the antitrust class action on that infringement is time-barred.

Parallel Proceedings: The Class Action Can Proceed While an Appeal Is Pending

One of the most practically significant features of the antitrust class action is the ability to run the class action proceedings in parallel with an ongoing appeal of the competition decision, in cases where the appeal challenges only the sanction or procedural aspects of that decision rather than the finding of infringement itself.

Where the challenge to the competition authority's decision is limited to the amount of the fine or to a purely procedural question — and not to whether the infringement occurred at all — the part of the decision establishing the infringement is already "no longer susceptible to challenge" for the purposes of Art. L 623-24. The irrebuttable presumption therefore applies, the five-year clock starts, and the association can file the class action summons without waiting for the sanction appeal to be resolved.

Why the Parallel Proceedings Rule Matters for Businesses

Businesses that appeal competition decisions on grounds relating to the sanction or procedure — a very common litigation strategy — should be aware that this appeal does not delay the opening of the class action window. If the infringement finding is not being challenged in the appeal, the irrebuttable presumption operates from the moment the appeal is filed (because the infringement finding is no longer challengeable), and the five-year limitation period for the class action begins at that point. An association can therefore initiate a class action while the business is still litigating the fine before the courts of appeal. The two proceedings run concurrently.

Provisional Execution of Consumer Information Measures

The antitrust class action includes one significant procedural advantage not available in the standard consumer class action: the court may order provisional execution of the consumer information measures — designed to inform consumers of the possibility of joining the group — before its decision has become final (Art. L 623-26).

Recall that in the standard consumer class action, consumer information measures cannot be implemented until the first judgment is no longer susceptible to any ordinary challenge or pourvoi en cassation (Art. L 623-7). This rule can significantly delay the consumer information phase if the defendant appeals, because the information campaign is locked until the appeal is resolved.

In the antitrust class action, the court has the power to order provisional execution of the information measures — meaning the consumer information campaign can begin even while an appeal is pending against the first judgment. This substantially accelerates the timeline from the professional's perspective and can increase consumer participation in the adhesion window.

The Provisional Execution Power: A Strategic Accelerator

The provisional execution of consumer information measures in the antitrust class action is not automatic — it requires a court order. But when ordered, it means that appealing the first judgment does not stop the information campaign from running. For a defendant business, this removes one of the key procedural advantages that an appeal would otherwise deliver in the standard class action. In competition cases — where the infringement is already established irrebuttably and the defendant's grounds for appeal of the class action judgment are therefore narrower — the information campaign will likely be ordered on provisional execution, making the gap between the first judgment and consumer adhesion shorter than in a standard consumer class action.

Antitrust vs. Consumer Class Action: The Key Structural Differences

Feature Standard consumer class action Antitrust class action
Legal basisC. consom. Art. L 623-1, 1°C. consom. Arts. L 623-24 to L 623-26
Prerequisite for liabilityCourt finds liability in first judgment on basis of individual cases presentedPrior final decision by competent authority/court establishing infringement — no longer challengeable on the merits
Can defendant re-litigate the infringement?Yes — liability is live in the first judgmentNo — irrebuttable presumption under Art. L 481-2 C. com.
Covered violationsAny legal or contractual obligation breach in sale/services/property rentalCartels (Art. L 420-1/TFEU 101), abuse of dominance (Art. L 420-2/TFEU 102), predatory pricing (Art. L 420-5). Concentrations excluded.
Limitation periodGeneral civil prescription rules apply5 years from exhaustion of challenges to the infringement finding (Art. L 623-25)
Can class action proceed while competition appeal pending?N/AYes — if appeal challenges only sanction/procedure, not the infringement finding
Information campaign — when can it start?Only after first judgment exhausts all ordinary appeals and pourvoi en cassationCourt may order provisional execution of information measures before judgment is final (Art. L 623-26)
Qualifying authoritiesN/AAutorité de la concurrence, French courts, European Commission, General Court, Court of Justice of the EU
Legal basis
StandardC. consom. Art. L 623-1, 1°
AntitrustC. consom. Arts. L 623-24 to L 623-26
Prerequisite for liability
StandardCourt finds liability in first judgment on basis of individual cases presented
AntitrustPrior final decision by competent authority/court establishing infringement — no longer challengeable on the merits
Can defendant re-litigate the infringement?
StandardYes — liability is live in the first judgment
AntitrustNo — irrebuttable presumption under Art. L 481-2 C. com.
Covered violations
StandardAny legal or contractual obligation breach in sale/services/property rental
AntitrustCartels (L 420-1/TFEU 101), abuse of dominance (L 420-2/TFEU 102), predatory pricing (L 420-5). Concentrations excluded.
Limitation period
StandardGeneral civil prescription rules apply
Antitrust5 years from exhaustion of challenges to the infringement finding (Art. L 623-25)
Class action during competition appeal?
StandardN/A
AntitrustYes — if appeal challenges only sanction/procedure, not the infringement finding
Information campaign — when can it start?
StandardOnly after first judgment exhausts all ordinary appeals and pourvoi en cassation
AntitrustCourt may order provisional execution before judgment is final (Art. L 623-26)
Qualifying authorities
StandardN/A
AntitrustAutorité de la concurrence, French courts, European Commission, General Court, Court of Justice of the EU
What Businesses Under Competition Investigation Need to Know
A competition authority investigation does not, by itself, trigger the antitrust class action. The action can only be filed once the authority's decision is no longer susceptible to challenge on the infringement finding. However, plan for the class action as a near-certain follow-on to any major competition enforcement proceeding.
The five-year clock starts when the infringement finding is final — not when the full decision (including sanction) is final. Where appeals challenge only the fine level, the limitation period begins from the filing of that appeal, because the infringement part is already no longer challengeable from that moment.
Appealing a competition decision only on the quantum of the fine does not delay the opening of the class action window or stop the class action from being filed while the sanction appeal is pending.
Once the irrebuttable presumption applies, the only defences remaining are on harm and causation: whether consumers suffered damage, whether that damage was caused by the infringement, whether it was passed on to commercial customers rather than end consumers, and the quantum.
The provisional execution of consumer information measures means that appealing the class action first judgment does not lock the information campaign the way it would in a standard consumer class action. Budget for the information campaign costs as a near-certain cost of a competition-based class action, even while the first judgment is under appeal.
The antitrust class action is only available for the three specified infringement types: cartels, abuse of dominance (including economic dependence), and predatory pricing. Harm arising from a merger or acquisition is not actionable through this route, even if the merger was problematic from a competition law perspective.
Competition enforcement decisions from other EU member state competition authorities are not expressly listed as qualifying decisions — the provision covers French authorities and courts and EU institutions. Businesses facing multi-jurisdiction competition enforcement should take advice on whether a foreign national competition authority decision can trigger the French class action.
Navigating the Antitrust Class Action Risk After a Competition Decision?

A competition authority decision establishing an infringement is not the end of a business's exposure — it may be the starting point of a consumer class action. Understanding the limitation window, the irrebuttable presumption, and the specific procedural differences from the standard class action is essential for planning the next steps.

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This article is for general information and educational purposes only. It does not constitute legal advice. Competition law is a specialised field; always seek qualified antitrust and consumer law advice when assessing exposure following a competition authority investigation or decision.