1.    Subject to subsection 2, if the insurer offers or purports to renew a policy at less favorable terms as to the dollar amount of coverage or deductibles or increases the rates in excess of fifteen percent, the new terms and new rates may take effect on the renewal date if the insurer has sent to the policyholder notice of the new terms and rates at least ten days prior to the expiration date. If the insurer has not so notified the policyholder, the policyholder may elect to cancel the renewal policy within the ten-day period after receipt of the notice. Earned premium for the period of coverage, if any, must be calculated on a pro rata basis and the rates must be based on the previous policy term.

2.    Subsection 1 does not apply if the change relates to guide “A” rates or excess rates also known as “consent to rate”.