The scientific research work carried out the analysis of the business model “Energy Service Company” (ESCO) used in foreign countries, examined legal regulations, as well as support mechanisms and other related circumstances. Energy service companies are investing their own or borrowed funds in the implementation of energy-saving projects and recover investments in full or in large part by energy savings. The available sources of information do not provide special laws or regulations governing the activities of the EPCOs or the players of these activities are not; however, this terminology is used in various directives, programmes and byelaws.