Tennessee Code Title 66. Property § 66-26-109

When a power or powers of attorney authorizing the sale or conveyance of real estate have been registered, whether with or without proper probate or acknowledgment, or any probate or acknowledgment at all, twenty (20) years or more in the register's office of the county where the real estate is situated, or, if the land lay within the Indian territory, then if registered in the register's office of any county in the state, such power or powers of attorney shall be deemed good and valid in law to pass the estate conveyed by the attorney or attorneys in fact; provided, that nothing contained in this section shall affect the rights of creditors or purchasers for valuable consideration, without notice.