Tennessee Code Title 4. State Government § 4-4-111

(a) When a department of state government or division of any department of state government renders services that are directly or indirectly incident to the duties of another department, then the department rendering such service may be reimbursed for the service by the other department out of the funds credited to the latter department, but such reimbursement shall only be made upon the approval of the commissioner of finance and administration.

(b) Such reimbursement shall be made either by actual payment or by the proper bookkeeping entry in the department of finance and administration prior to the end of the fiscal year in which such services were rendered.