Tennessee Code Title 56. Insurance § 56-7-1303

(a)(1) No notice of cancellation of a policy shall be effective unless mailed or delivered by the insurer, its authorized agent or employee, to the named insured as shown in the policy declarations at the address shown in the declarations, stating when not less than twenty (20) days thereafter the cancellation shall be effective; provided, the policy may be cancelled by the company by mailing to the insured written notice stating when not less than ten (10) days thereafter the cancellation shall be effective, if:

(2) The mailing of the notice shall be sufficient proof of notice.

(3) The effective date and hour of cancellation stated in the notice shall become the end of the policy period, unless the insured surrenders the policy and requests cancellation prior to the date and hour specified in the cancellation notice.

(4) Delivery of the written notice either by the insured or by the company shall be equivalent to mailing.

(b)(1) If the reason or reasons for cancellation are not included in the notice of cancellation, then at the written request of the named insured, mailed or delivered to the insurer not later than fifteen (15) days subsequent to the effective date of cancellation, the insurer shall specify any and all reasons for the cancellation. This subdivision (b)(1) only applies to policies that have been in force sixty (60) days beyond the initial effective date.

(2) Every renewal policy shall be presumed to be in effect for at least sixty (60) days. Any notice of cancellation shall advise the insured that the insured may request the reasons for cancellation by written request mailed or delivered to the insurer not later than fifteen (15) days subsequent to the effective date of cancellation.