Subject. This article considers the issues of harmonization of tax regimes and reform of special tax ones. Objectives. The article aims to determine areas to improve the tax system, harmonize the General Tax System and special tax regimes, and involve business entities applying special tax regimes in the VAT movement. Methods. For the study, I used the methods of logical analysis and synthesis, induction and deduction. Results. The article offers a concept of harmonization of the General and Simplified Tax Systems, and the Unified Agricultural Tax. As well, the article substantiates the need to combine the Simplified Tax System and Unified Agricultural Tax, and limit the marginal gain for the application of special tax treatments. Conclusions and Relevance. The preconditions that led to the introduction of the Simplified Taxation, Unified Agricultural Tax and Unified Tax on Imputed Income special tax treatments are not relevant today. A fresh approach to special tax regimes is needed in the context of the digitalization of the tax system. The results obtained can be used in legislative activities to reform the tax system.