The state acquires its current and regular revenues in the form of taxes, customs duties, fees, charges, contributions and public debt. Taxes are one of the most important revenues with which the state covers expenditures. An attractive tax system is based on four important principles: enforceability and simplicity, fairness, resilience and generosity, and economic efficiency. The state has its own costs, ie expenditures, so it must have revenues in order to cover the costs. When it happens that revenues are less than expenditures, the state must borrow. In order for changes to take place in the country, it is necessary to change the economic, social and political system. For the change to be successful, there must be a change in the tax system.At the time when Croatia was part of Yugoslavia, the tax system consisted of direct and indirect taxes. Direct taxes referred to natural and legal persons, and indirect tax was sales tax. The main complaint in the tax system in the Republic of Croatia is tax instability due to frequent changes in tax regulations. According to the data, it was recorded that in the period from 2012 to 2015, there were 44 changes or amendments to tax regulations. The constant change of tax regulations leads to insufficient knowledge of the tax system by entrepreneurs, citizens and even the employees of the tax administration.