In calculating their annual earnings from the mine, operators can deduct the depreciation allowance in respect of class 1, class 2, class 3 and class 4 property they use in connection with a mining operation.

In calculating the mine-mouth output value for a fiscal year, operators can also deduct the depreciation allowance in respect of class 1A, class 2A, class 3A and class 4A property they use in connection with a mining operation. In such a case, they must deduct the same amount in calculating their annual earnings from the mine.