Introduction: In contrast to neoclassical economics, where agents are rational, their actions are rational, and they strive for equilibrium, complex economics proposes to consider systems as evolving, complex, and not necessarily striving for equilibrium. The application of complex economics is particularly relevant in conditions of uncertainty and rapidly changing economic conditions. To develop the tools of complex economics, it is necessary to search for new mathematical approaches; a revolutionary approach in economics could be an approach based on the formalism of phenomenological theory. Methods: The formalism of phenomenological theory is used. Results: Four economic models are considered that can be built using the formalism of phenomenological theory. Using the example of analyzing changes in economic indicators caused by external factors such as magnetic storms, a modeling algorithm was implemented using phenomenological theory. Available data: No available data Discussion: The article shows that phenomenological formalism can be used in both traditional and more modern economic paradigms, expanding the boundaries of theoretical and applied analysis. Based on observed patterns and empirical data, phenomenological models allow us to study the macroscopic characteristics of economies without delving into microscopic details. As shown above, the formalism of phenomenological theory can be used both within the framework of neoclassical economics and complex economics. The phenomenological approach is universal and applicable in various areas of economic analysis, and the use of phenomenological theory allows us to take into account the elements of randomness and irrationality inherent in real economic processes, which is especially relevant for a complex economy.