The terminological phrases which defined the phenomenon of joining territorial collectivities are different but the core is much the same. The intercommunality or joining territorial collectivities refers more often to the mechanism for ensuring the efficiency of public services. EU Member states developed their own legal framework for organization and functioning the associations of intercommunity development. The fundamental problems dealing with the concept of intercommunity joining as well as the legal basis for functioning and organization of these structures represent the purpose of analysis in this study. The Legislative approaches in the field of intercommunity joining is the solution for overcoming some common problems: the legal complexity regarding the organization, the competencies integration, the autonomy of decision making. The extent to which this approximation can be achieved is determined by the degree of understanding the concept of intercommunality, the purpose and the probable effects.