This paper clarifies the general concept of electronic business, from history to the application of modern technology, with an emphasis on the importance of electronic literacy. The advantages and disadvantages of electronic business are also described. In the continuation of the paper, the concept and developments of e-administration, its application in public administration and the description of the e-citizen system are explained. In the practical part, the business of the Tax Administration, electronic services and the management of authorizations are discussed in more detail. Individual e-tax applications and services are explained in detail, such as tax bookkeeping cards, forms, requests and the user box, viewed from the perspective of use by taxpayers themselves, as well as by Tax Administration officials. A comparison and experience in the use of e-tax in relation to e-citizens is made, as well as a comparison of the Estonian and Croatian Tax Administration. In the analytical part, research and a survey on the efficiency, satisfaction and application of e-tax by the employees of the PU more specific branch are carried out, and the results are analyzed. At the end of the paper is the conclusion of the topic, with a focus on electronic business in the Tax Administration now and in the future.