Tenn. Code § 56-2-109
The failure of a company to obtain a certificate of authority shall not impair the validity of any act or contract of the company, and shall not prevent the company from defending any action at law or suit in equity in any court of this state; but no company transacting insurance business in this state without a certificate of authority shall be permitted to maintain an action at law or suit in equity in any court of this state to enforce any right, claim or demand arising out of the transaction of insurance business until the company has obtained a certificate of authority, nor shall an action at law or suit in equity be maintained in any court of this state by any successor or assignee of the company on any right, claim or demand originally held by the company until a certificate of authority has been obtained by the company or by a company that has acquired all or substantially all of its assets.
T.C.A. § 56-2-109