The purpose of this paper is to analyse the legal regulation of cross-border commercial agency agreements in two main legal systems: civil law and common law. It should be noted that the legal regulation of international commercial agency agreements is fragmented; therefore, the general principles of agency law could be applied in order to propose sustainable solutions in international commercial agency relationships. In this paper, the authors consider the effectiveness of these general rules in commercial agency agreements and conclude that the lack of common international regulation for leads to the application of conflicting national rules that are not sufficient in aligning the sustainable interests of all parties of such complex legal relations.