||Abstract The subject of this thesis is electronic records (EET) of sales and its implementation in the Czech Republic. Because one of the main goals is to improve tax collection the first part of the theoretical section of the thesis is devoted to a brief introduction to taxes and specifically the value-added tax. The second part of the theoretical section is describing the specifics of the Czech version of electronic records of sales. First, a few models of records of sales are described and which of them was chosen and why. Then this model is described in detail, including who has to abide by it, what sales they have to record and some of the technical aspects of the system. A part is also dedicated to the associated receipt lottery and the end of the theoretical section is devoted to similar systems of electronic evidence of sales and their impacts in other countries. The practical section of the thesis is devoted to answering the question if the introduction of electronic records of sales in the Czech Republic was justified, based on fulfillment of its initial goals. The main goals were to increase the tax revenue and lowering the size of the shadow economy. In order to verify the estimate of increase in VAT revenue due to introduction of EET, calculated by the Ministry of Finance, I calculate my own estimation and compare them. Apart from these goals, the practical section is also evaluating the costs of the whole project and also some public concerns are addressed. The thesis ends with a brief look at the future of records of sales in the Czech Republic.