The non-self-employment income tax is present in the life of every individual who has an established employment relationship. Progressive tax, the amount of which is determined according to the system of each country by sending pre-determined tax rates. The progressiveness of each individual tax system is manifested through several tax brackets covering different income levels. Throughout history, the classes and tax rates that apply to individual amounts of income have changed, and today in the Republic of Croatia there is a system of two tax rates for two categories of income. The aim of this paper is to present in detail the income tax system in the Republic of Croatia and compare it with the two tax systems of the European Union, Austria and Germany, and to explore similarities and differences. With the accession of Croatia to the European Union, the trend of migration is more and more present, which encourages the research of various political, economic and economic systems. The subject of this paper is an overview of different tax brackets and rates and their impact on the amount of final net salary. The paper mainly explains the tax on income from non- self-employment, but also mentions other forms of tax that make up the tax system of a country. The intention was to process and present the components of the calculation of the salary of an individual country, thus summarizing the main similarities and differences of the three researched systems. During the research and writing, secondary data sources, professional and scientific members and other literature related to field research were used.