Tenn. Code Ann. § 67-3-501

Except as otherwise provided in this part, the taxes imposed by §§ 67-3-201 — 67-3-203, and the fee imposed by § 67-3-204, on taxable petroleum products measured by gallons removed from the terminal rack, shall be paid by the licensed permissive supplier, if the supplier has entered into a blanket pre-collection election as provided in § 67-3-503, or if the supplier has entered into an agreement with a customer whereby Tennessee petroleum products taxes and fees are levied on the sale of fuel to that customer. The taxes and fees are due on or before the twentieth day of the month following the month of removal, unless such day falls on a weekend or state or banking holiday, in which case the taxes and fees are due the next succeeding business day.