When an insurance carrier certifies a motor vehicle liability policy under AS 28.20.410 or 28.20.420 the insurance certified may not be cancelled or terminated until at least 10 days after a notice of cancellation or termination of the insurance is filed with the department, except that a policy subsequently procured and certified shall, on the effective date of its certification, terminate for the purpose of this chapter the insurance previously certified for a vehicle designated in both certificates.