In the context of an action for damages for harm suffered as a result of a infringement of competition law, Article L. 481-4 of the Commercial Code allows the defendant to plead, as a defense against a claim for damages, the fact that the plaintiff has passed on, in whole or in part, the additional costs resulting from the infringement of competition law. The aim is to prevent the plaintiff in the action from enriching himself by claiming compensation for damage that he has already passed on to his own customers. The burden of proof of the passing on of the additional costs and the extent thereof lies with the defendant, who may reasonably require the production of information by the plaintiff or third parties.

When the action is brought by an indirect purchaser, Article L. 481-5 establishes a simple presumption that the additional cost has been passed on by its seller, provided that it can be shown that the defendant has committed an infringement of competition law, that the practice has resulted in additional costs for the defendant’s direct contractor, and that the defendant itself has purchased the goods or services affected by the anticompetitive practice, or purchased goods or used services derived from or containing them.