Given the challenging conditions of sanctions and uncertain external economic environment, it is essential for coal producers to project their economic health in the short and long term. This purpose requires to have forecast tools with respect to the development of an enterprise and its future financial flows under various initial conditions and the impact of negative external environment factors. This study aimed to develop a tool for dynamic assessment of financial flows of a coal producer in form of an economic and mathematical operating model. The framing methods for this model are based on the cash flow pattern of an enterprise, including proceeds from the sale of products, receivables, payables and production costs, as well as loan repayments. The model accounts for the time value of money and is dynamic, as it allows to estimate the balance of cash flows for several periods (months, quarters, years) ahead. The dynamic model is based on the assessment of the input financial parameters of a coal producer, the determination of the rules of cash flow management, the calculation of the changes in cash flows for the period concerned and the calculation of the financial parameters of a coal producer at the end of the period under consideration. The model allows to estimate the financial flows of a coal producer for several future periods with different input data. The dynamic model allows to assess the financial condition of a coal producer against the background of the changing financial flow management rules in conditions of uncertainty and Western and US sanctions. The application of the model in planning the performance of coal producers will optimize financial flows and create an effective plan of the enterprises’ activities in complex and unstable economic conditions. The proposed model may be further developed to clarify and account for disrupting factors and to computerize dynamic modeling.