The paper analyzes tariff and non-tariff barriers and their impact on the economy. Tariff barriers represent a complex set of measures that a country applies to control the import and export of goods across its borders. Non-tariff barriers can be described as all measures and procedures applied by one or more countries to hinder free international trade. The paper is structured into three parts. In the first part, I explore the concept of customs and the traditional use of customs barriers as a means of protecting the domestic economy from foreign competitors. This part also includes a discussion about the division of customs duties, the costs and benefits of introducing customs duties, examples of customs barriers in world trade, the reactions of individual countries to changes in customs barriers, and the measurement of customs barriers. In the second part of the paper, there is a detailed analysis of non-tariff barriers, which have currently become the main instrument for the protection of domestic economies. The classification of non-tariff barriers and their establishment are analyzed. Non-tariff barriers are divided into three categories: traditional, technical, and administrative, and each is explained individually. The third part of the paper is dedicated to the system and policy of trade in the European Union, where I will analyze the common trade policy of the European Union, the trade policy of the European Union towards third countries, and the bilateral agreements of the European Union.