The administration of taxes and fees was one of the main concerns of the state which during the evolution of this system introduced and revised different techniques and methods to achieve its economic and social needs. In this research, the method of taxation of taxpayers from a sector well defined by the legislator, the subject entities of the small and medium enterprises sector, which over time has undergone a certain metamorphosis with regard to some adjustments and additions, is examined. The diversification of the taxation system, its adaptation to the real needs of small entrepreneurs who have a multilateral influence on economic development, is one of the main techniques for supporting and defending this sector, a fact for which various scholars and experts in the field have dedicated numerous researches in this area sense. The practice of diversifying taxation regimes is not only an identification of the optimal regime for certain economic agents or fields of activity, but also a tendency to respect a basic principle of taxation, the principle of fiscal equity. The basis of this principle is the differentiated taxation of income and wealth according to the contributory power of the subject.