The scientific problem discussed in the article is to determine the essence of the creation of the Customs and Tax Service as a result of the reform of the tax administration in Poland in 2017 and to assess the correctness and legitimacy of its functioning in comparison with the functioning of the Border Guard. The paper uses the formal-dogmatic method based on the analysis of legal acts, which is the main method used in legal sciences. The method of critical analysis of the literature was also used. The Customs and Tax Service was established by the Act of 1 March 2017 on the National Revenue Administration together with the reform of the tax administration, combining the Customs Service and the tax administration authorities, while the Border Guard operates on the basis of the provisions of the Act of 12 October 1990 on the Border Guard. Both of these services are uniform, uniformed and armed formations designed to protect the state border, control traffic at the state border and ensure the protection of the customs territory of the European Community (Customs and Revenue Service) or counteract illegal migration (Border Guard). The same scope of many powers raises doubts as to the legitimacy of the creation of the Customs and Revenue Service and, consequently, as to the functioning of two uniformed formations performing, as the analysis shows, many of the same or similar tasks. In addition, the same issue of duplication of powers has been identified with regard to officers and officials of the National Revenue Administration. The question is whether such a solution and division of tasks should continue to function. The results of the findings clearly indicate that most of the tasks of the Customs and Revenue Service are duplicated with those of the Border Guard, and the tasks that currently lie solely within the competence of the Customs and Revenue Service could be distributed among the already functioning formations.