Tennessee Code Title 56. Insurance § 56-7-1806

(a) In the event an insurance company intends to increase the premiums of a commercial risk policy by an amount that is more than twenty-five percent (25%) and the increase in premium is the result of comparing policies of equivalent exposures, the insurance company shall mail or deliver to the named insured and producer at the address shown on the policy, not less than sixty (60) days prior notice of its intention to increase the premiums, specifying the percentage of the increase.

(b) Unless notice is provided as described in subsection (a), the insurer is required to extend the existing policy sixty (60) days from the date the notice is provided.

(c) The premium for the policy provided in those circumstances shall be not more than a pro rata basis of the existing policy.