The article considers the specifics and features of application of the simplified taxation system in Ukraine. Small business entities can apply either general or simplified taxation system. On the basis of generalizations of literary sources and current practice, the advantages and disadvantages of the simplified system at the present stage of economic development are determined. The biggest advantages of the simplified taxation system are tax advantages, which consist in the absence of the obligation to pay certain types of taxes, as well as a simplified system of accounting and reporting for small business entities, the ability to take into account the socio-economic situation of a particular geographic area, because a single tax has to be paid to the local budget. The disadvantages are primarily associated with abuse by economic entities and their evasion of payments. Four groups of single tax payers are characterized depending on the level of annual income, the number of employees and legally established rates. The dynamics of single tax receipt is analyzed and its share in the structure of tax revenues to the Consolidated Budget of Ukraine for 2016-2020 is determined. The proportion of the single tax in the context of taxpayers for 2016-2020 is determined and it is found that the largest share of this tax comes from individual entrepreneurs. The actual problems of functioning of the simplified taxation system in Ukraine are distinguished. The main legally justified reforms are analyzed: new limits for individual entrepreneurs and introduction of registrars of settlement operations. Some changes and postponements in the legislation in connection with the COVID-19 pandemic are noted. As a result, conclusions are drawn about the need to reform the simplified taxation system, which should be aimed at improving it along with preventing abuse.