When an insurance carrier has certified a motor vehicle liability policy under RCW 46.29.460 or 46.29.470 the insurance so certified shall not be canceled or terminated until at least ten days after a notice of cancellation or termination of the insurance so certified shall be filed in the department, except that such a policy subsequently procured and certified shall, on the effective date of its certification, terminate the insurance previously certified with respect to any vehicle designated in both certificates.
RCW 46.29.500