As a result of developments in information and communication technologies and globalization, existing taxation rules cannot meet the needs of the day. The digitalization of the economy increases existing problems and requires digital transformation of tax rules on a world scale. The main challenges in the taxation of digital economy arise from the loss of importance of physical existence. The inability to fully solve this problem leads to a serious base erosion problem at the global level. Therefore, it is important to examine the taxation problems caused by digitalization and to reveal the differences between the tax practices of countries. In this direction, the aim of the study is to examine the challenges encountered in taxation of digital economy and the effect of digitalization on tax base and to examine the unilateral measures of the countries in this regard.