Under current circumstances, the imperfect conditions of economic activity, which are formed in the country, have a significant influence on the macroeconomic situation. As a result, the economically unreasonable tax legislation, aimed at instantaneous replenishment of the budget, leads to an excessive tax burden on the real sector of the economy and the formation of its shadow segment. The use of shadow transactions to conceal the tax revenue is a manifestation of deeper processes of redistribution of the gross domestic product in favour of the shadow economy and requires active measures aimed at improving the tax system. The main objective of the article is to consider a way to improve the existing fiscal mechanism by identifying the main reasons for the implementation of shadow operations and the transmission features, as well as to determine the directions of increasing the influence of the fiscal mechanism on reducing the shadow sector of the economy. The article reveals the influence of the fiscal mechanism on the unshadowing of the economy through the formation of a fiscal transmission in the Ukrainian economy as a process of successive transfer of impulses of the fiscal policy of the state, reflecting the relationship between tax instruments and business activity in the real sector. The main channels of fiscal transmission are five types of taxes that are defined by the Tax Code of Ukraine: corporate profit tax, income tax, value added tax, excise tax and duty. Each tax becomes a transmission channel of the fiscal impulse in the process of determining its main components and due to their transmission; a positive effect of unshadowing in the short run is achieved. However, to do this, support for the fiscal impulse should be ensured through changes in related areas of activity and the efficient management of taxation, which includes monitoring of the indicators of the taxpayers activities, performance by the fiscal authorities explanatory work of the tax legislation and introducing an effective tax administration system. [ABSTRACT FROM AUTHOR]