On June 23, 2026, the European Commission published a Joint Statement issued by the European Competition Network (“ECN”) that addresses the enforcement of merger call-in mechanisms by national competition authorities across the European Economic Area. The Statement targets businesses involved in sub-threshold transactions such as start-ups (killer acquisitions), roll-up strategies, mergers in highly concentrated local markets, and deals in low-turnover sectors, that do not meet standard notification thresholds but may still impact competition. The ECN emphasizes that call-in powers – which should be used on a case-by-case basis by national enforcers and in principle be limited to a pre-defined period – should be exercised only when such transactions could have material anticompetitive effects, aligning with obligations under the Digital Markets Act for gatekeepers to inform the European Commission of intended acquisitions. The guidance calls for jurisdictions interested in introducing call-in mechanisms to establish clear rules to balance effective enforcement with legal certainty and for reduced administrative burdens.