(a) On or before the 20th day of the second month following the month in which gas was purchased from a producer, the first purchaser must file a report with the comptroller on forms prescribed by the comptroller. The report must contain the following information concerning gas purchased from a producer during the month being reported:
(1) the gross amount of gas purchased from each producer;
(2) the price paid for the gas;
(3) the leases from which the gas was produced; and
(4) other information the comptroller may reasonably require.
(b) If the report the first purchaser is required to file shows any additional tax due, the first purchaser must pay the tax when he files the report.