Assessment Of Tax

(1) The owner of coal products shall become liable for the tax imposed at T.C.A. §67-5902 at the time the coal products are ready for sale, regardless of whether such coal products have been processed prior to sale or not. (2) The basis for the computation of the tax shall be the total weight of the coal products sold regardless of whether the coal products are sold in their processed or unprocessed state. (3) In addition to any other information the commissioner may require and for the purpose of ascertaining the amount of tax due, all persons subject to the tax shall maintain, for a period of four (4) years, records showing the total weight of coal products sold from each production unit, and the total weight of coal products severed from the earth at each production unit ant the total amount of any royalties paid on coal products severed from the earth at each production unit. These records shall be open to inspection by the commissioner or his agents at any time during normal business hours.