Tenn. Code Ann. § 67-3-301: Measurement of gasoline tax

The tax imposed by § 67-3-201 on taxable gallons imported into this state by a licensed importer shall be measured and levied at the time the product first comes to rest in this state. On a product refined, produced, or compounded in this state, the tax shall be measured and levied on any finished product when first placed into storage for sale or use. For a product removed from a qualified terminal or refinery outside this state, destined for this state under a tax precollection election provided in § 67-3-503 , the tax shall be measured and levied at the time the product is removed across the terminal rack of such out-of-state facility, as if the product were imported and came to rest in this state.