(1) No notice of cancellation of a policy to which section 10-4-602 applies shall be valid unless mailed or delivered by the insurer to the named insured at least thirty days priorto the effective date of cancellation; but, where cancellation is for nonpayment of premium, at least ten days' notice of cancellation accompanied by the reason therefor shall be given or, alternatively, a notice advising that the policy will be cancelled if timely payment of premium is not made may be given at least ten days but not more than thirty days prior to the premium due date. Unless the reason accompanies or is included in the notice of cancellation, the notice of cancellation shall state or be accompanied by a statement that, upon written request of the named insured, mailed or delivered to the insurer not less than fifteen days prior to the effective date of cancellation, the insurer will specify the reason for such cancellation. As used in this section, "premium due date" means the date that a premium that has been previously paid is fully earned.

(2) Where the reason for cancellation does not accompany or is not included in the notice of cancellation, the insurer shall, upon written request of the named insured, mailed or delivered to the insurer not less than fifteen days prior to the effective date of cancellation, specify in writing the reason for such cancellation. Such reason shall be mailed or delivered to the named insured within five days after receipt of such request.

(3) This section shall not apply to nonrenewal of a policy.