We study the effects of completing the legal framework of matchmakers with a rule designating which party must pay the commission. The paper examines the two rules currently open to debate at the international level in sport: the “player-pays” principle and the “club-pays” principle. We find that the most appropriate measure entails designating the party with the lesser bargaining power to pay the intermediary’s fee. However, our main result indicates that the appropriateness of imposing an additional rule in the legal framework is a preliminary issue. Indeed, even if the best rule is chosen, welfare may be decreased by this legal initiative.