(1) Every industry participant who is liable to pay a wholesale gas levy for a month must supply to GIC a return no later than the due date for payment of the levy for that month, unless otherwise agreed by GIC.
(2) The return must state—
(a) the total number of gigajoules of gas that the industry participant purchased directly from gas producers during the previous month; and
(b) how many gigajoules of gas were purchased from each gas producer during that month.