Účetní a daňové aspekty podnikání fyzické osoby při souběhu se zaměstnáním

This bachelor’s thesis deals with the tax and insurance contribution obligations of self-employed persons in the Czech Republic, particularly in situations where self-employment is combined with employment. The aim of the thesis is to analyse the legal framework, tax obligations, and social and health insurance contributions in various scenarios involving combined sources of income. The theoretical part first defines the basic concepts, including who is considered a self-employed person, the distinction between primary and secondary self-employment activity, and the principles of maintaining records of income and expenses. The thesis also examines the taxation of personal income and the system of social and health insurance contributions, especially in situations where an individual has income from multiple sources. The practical part contains five model scenarios simulating different combinations of employment and self-employment, ranging from higher business income to occasional additional earnings. These examples demonstrate the differences in monthly financial burden between primary and secondary self-employment activities. The thesis also compares the use of flat-rate expenses with actual documented expenses. The results show that secondary self-employment activity is financially less burdensome in cases of lower income; however, it also involves certain risks. If profits increase and exceed the statutory threshold, high additional insurance contributions may arise retrospectively. In contrast, primary self-employment requires the payment of monthly advances regardless of the level of profit.