Tenn. Code Ann. § 67-1-1302: Persons subject to subpoena power

It is the declared intent of this part that all persons, firms or corporations whatsoever having any knowledge pertaining to liabilities for taxes or fees due the state of Tennessee, and any books, papers, records or other data pertaining to liabilities for taxes or fees due the state of Tennessee, shall be subject to the subpoena power granted under this part.