Section 78.58 - Reports to department; computation of tax(1) REPORTS OF GENERAL AVIATION FUEL LICENSEES. (a) For the purpose of determining the amount of the licensee's liability to the state for the tax imposed by this subchapter, except as provided in par. (b), each general aviation fuel licensee shall, not later than the 20th day of each month, file a monthly report for the next preceding month. The licensee or the licensee's duly authorized agent shall sign the report.(b) The department may allow a licensee whose tax liability is less than or equal to $500 per quarter to file on a quarterly basis. The licensee shall file the quarterly report for the next preceding quarter on or before the 20th day of each quarter.(2) REPORTS OF OTHERS. Any person, not a general aviation fuel licensee, who places any general aviation fuel in the fuel supply tank of an aircraft in this state upon which the general aviation fuel tax has not been paid or the liability therefor has not been incurred by any general aviation fuel licensee in this state, shall file a report and make payment of the tax on the general aviation fuel and shall be subject to this chapter in the same manner as is provided for general aviation fuel licensees.(3) COMPUTATION OF TAX. Each general aviation fuel licensee at the time of making the monthly or quarterly report shall compute and pay the full amount of the general aviation fuel tax for the next preceding month or quarter, which shall be computed as follows: the number of gallons of general aviation fuel placed into the fuel supply tanks of an aircraft or into bulk storage facilities by the general aviation fuel licensee, multiplied by 0.06 and the resulting figure expressed in dollars.1981 c. 20; 1993 a. 16; 1997 a. 27, 41.