The observance of the degree of exigibility of firm’s liabilities from the extraction sector needs the formation of longterm provision at the minerals extraction phase in order to cover the consumption of quarry rehabilitation and to turn it into short-term provision. We know that during the business year the firm would reflect the use of the mentioned provision and its adjustment to the change of the extraction conditions and of the rehabilitation of the quarries from which mineral production was extracted. At the end of the business year it is necessary to make the inventory of the formed and used provision. These data are considered when solving the problem of establishing deductible expenses for tax purposes.