Coal mining is one of the most important sectors of the Polish industry. It can be said that the coal is a national raw material. This results in Poland being a pioneer in the European Union in terms of coal mining as well as its use in the production of electricity and heat. There are many companies in Poland which have been established and developed around the coal mining industry aimed at coal extracting. The operations of those companies depends on the condition of the mining companies and their cooperation with them: commercial, service and advisory, called referred to as “mining supporting companies”. The article focuses on the results of a survey carried out in mining supporting companies, such as mining machinery and equipment manufacturers, mining-related service companies and mining-related research and development institutions. The authors evaluated the relationship and dependence of those companies on the mining industry. It was assumed that the measure of the mining supporting companies condition is the overall quantity of public related payments contributed to the state budget and local budgets. In the article, the authors raised the problem of the size of losses for public finances, as a result of the significant limitations of financial flows from the mining companies. The surveyed companies are those associated with the Polish Mining Chamber of Industry and Commerce. As a result, the authors prepared conclusions regarding the dependence of the mining supporting companies on the situation of the mining subsector.