Suppliers of petroleum products should invoice and bill their customers using net gallons, and taxes should be reported based on net gallons. Net gallons are temperature and pressure adjusted gross gallons. If a supplier, wholesaler or bonded importer bills a customer in gross gallons instead of in net gallons, the Department of Revenue will make an assessment for any additional taxes collected plus applicable penalty and interest.
Reference: Tenn. Code Ann. 67-3-701.