ADDITIONAL TAX APPLIES TO INVENTORIES.

(a) On the effective date of an increase in the rates of the taxes imposed by this chapter, a distributor or dealer that possesses for the purpose of sale 2,000 or more gallons of gasoline or diesel fuel at each business location on which the taxes imposed by this chapter at a previous rate have been paid shall report to the comptroller the volume of that gasoline and diesel fuel, and at the time of the report shall pay a tax on that gasoline and diesel fuel at a rate equal to the rate of the tax increase.

(b) On the effective date of a reduction of the rates of taxes imposed by this chapter, a distributor or dealer that possesses for the purpose of sale 2,000 or more gallons of gasoline or diesel fuel at each business location on which the taxes imposed by this chapter at the previous rate have been paid becomes entitled to a refund in an amount equal to the difference in the amount of taxes paid on that gasoline or diesel fuel at the previous rate and at the rate in effect on the effective date of the reduction in the tax rates. The rules of the comptroller shall provide for the method of claiming a refund under this chapter and may require that the refund for the dealer be paid through the distributor or supplier from whom the dealer received the fuel.