The aim of the main part of the contribution will describe the gradual development and the steps of the electronization of public, or tax administration. Since the year 2002 operates the application EPO, through which taxpayers have the possibility to submit their tax returns. In the year 2008 the major change occurred when in fact was switched from email communications with tax authorities to the server solution. The crucial part of the contribution will be the discussion of the data boxes, which are now in the process of implementing and running, which itself raises a number of issues and practical problems. Data boxes were introduced into Czech law by the so-called E-government act, which is the Act no. 300/2008 Coll., on electronic acts and authorized conversion of documents, as amended. We will also take into account the Act no. 365/2000 Coll. on public administration information systems and amending certain laws, as amended, which should cause a revolution in public administration by starting a massive scale of using on-line communication.