Except in Calvert County, Carroll County, Charles County, St. Mary’s County, and Washington County, a hotel is allowed, for administrative costs, a discount equal to 1.5% of the gross amount of hotel rental tax collected if, on or before the due date, the hotel: files the hotel rental tax return; and pays the hotel rental tax. In Calvert County, Carroll County, Charles County, St. Mary’s County, and Washington County, the county commissioners may determine whether a hotel is eligible to receive a discount.