Tenn. Code Ann. § 67-8-210

The commissioner of revenue shall account to the comptroller of the treasury for all moneys so collected monthly, less not more than two and one-half percent (2.5%) thereof for expenses of administration, who shall receipt therefor and forthwith pay over to the state treasurer all moneys thus received, who shall place the moneys to the credit of the general fund; provided, that the commissioner shall retain in the commissioner's hands at all times such a sum as, in the commissioner's judgment, shall be sufficient to enable the commissioner to pay promptly all claims for refunds as provided for in § 67-8-208.