In its judgment of 30 October 2025, the Belgian Court of Cassation held that the duration of a competition law infringement is inextricably linked to the finding of the infringement itself. On that basis, it annulled the Market Court’s decision for having artificially distinguished between the existence of the infringement and the determination of its temporal scope. It confirms that duration is not merely an accessory element but a constitutive component of the infringement. Accordingly, the failure to clearly articulate this framework does not merely affect an ancillary aspect of the decision, but undermines the integrity of the infringement finding as such.
Beyond its immediate procedural consequences, the judgment carries broader doctrinal significance. It unequivocally confirms that the temporal dimension of anticompetitive conduct cannot be relegated to a secondary or merely accessory consideration where it forms part of the legal characterisation of the infringement. In such circumstances, a deficiency relating to duration does not merely affect the adequacy of the statement of reasons, but may call into question the validity of the infringement finding itself. In doing so, it delineates the limits of partial annulment and underscores the centrality of duration as a defining parameter of liability.