In the context of the reform of state control and supervision in the financial sector, new instruments of control and supervision are being generated, which include monitoring. Using the example of tax and customs monitoring, the article highlights and substantiates current trends in the legal regulation of control and supervisory activities in the modern period. The author identifies the general and distinctive features of tax and customs monitoring, substantiates the current directions of their legal regulation. As common features of the institutions under consideration, the following are highlighted: the conditionality of their generation by the digital transformation of state control and supervision, elements of dispositivity, increased transparency of interaction, the role of self-control, limited use, and the development of individual legal regulation. Various formats of regulatory consolidation and criteria for limiting the use of monitoring are indicated as differences between tax and customs monitoring. To achieve the stated goal, methods of system analysis, synthesis, classification, comparative legal and formal legal methods were used. The novelty of the conducted research lies in the proposed options for the theoretical and legal positioning of monitoring as a tool of control, a type of public service, a tool to achieve a balance of private and public interests. The analysis made it possible to identify the features of monitoring used in the tax and customs spheres, which form new approaches to modern tools of state control and supervision in the financial sector. It is concluded that monitoring is positioned as an instrument of the appropriate type of control. At the same time, tax monitoring is clearly defined by the legislator as a new form of tax control, in the centralized sphere of control and supervisory influence, monitoring is understood as a special regime of remote state control (supervision), and the legal status of customs monitoring at the regulatory level in the customs control system is currently not defined. The conclusion is made about the proximity of monitoring to public services, which is reflected in the sign of voluntary participation in the mechanisms of tax and customs monitoring.