Abstract: The study of legal terms and phenomena helps researchers to better understand the process of knowledge, more deeply reveal the processes of formation and evolution of individual concepts and the relationships in the field of study, restore past events and give them a legal assessment taking into account modern advances in science. In this regard, the author of the article examines the formation and development of the concepts of "transit", "customs transit", consistently analyzes the sources of law which may contain an indication of the concepts under study and draws appropriate conclusions. This study was conducted using both general and special research methods. The author analyzes the sources of law which may contain an indication of the concepts under study and concludes that the main meaning and content of the term “customs transit” has deep historical, political and economic roots. Historical agreements on passage, transportation “along the way, without sale” influenced the strengthening of relations between individual principalities and states, contributed to the development of trade. Currently, the term evolves from “passing along the way, without marketing” to the term “customs transit”, the legal framework of legal relations within its framework and consolidation in regulatory legal acts acts to strengthen the political ties of the state, positively affect the development of foreign economic relations, trade, growth business and income to the treasury of the state.