The article is devoted to the characteristic of the legal basis for the construction of financial legal terms in Ukrainian legal norms. The main attributes of financial legal terms, used in Ukrainian financial law, are proposed. The article shows that the task for the legislator in the formulation of specific financial legal terms is formalizing the specific legal phenomena of social life through its legal regulation and identifying of it’s essential characteristics. The conclusion about the importance of legal definitions in financial legal norms is made considering the development of financial relations and the need to build a logical system of financial legal norms.