The sales price includes the total amount received by the seller for the transaction. If the seller is reimbursed by a third party for a coupon, e.g., a manufacturer’s coupon, the sales tax is due on the sales price before the coupon is applied. Here, the seller would still receive the full sales price for the transaction – partly from the consumer and partly from the third party. If the coupon is a dealer discount coupon, and the seller is not reimbursed by a third party, then the amount the seller actually receives is what is paid by the customer. In this situation, the seller would collect sales tax on the sales price after the coupon is applied.
Reference: Tenn. Code Ann. § 67-6-102(85).