Wash. Rev. Code § 48.19.310
Every rating organization and every insurer which makes its own rates shall provide within this state reasonable means whereby any person aggrieved by the application of its rating system may be heard, in person or by his or her authorized representative, on his or her written request to review the manner in which such rating system has been applied in connection with the insurance afforded him or her. If the rating organization or insurer fails to grant or reject such request within thirty days after it is made, the applicant may proceed in the same manner as if his or her application had been rejected. Any party affected by the action of such rating organization or such insurer on such request may, within thirty days after written notice of such action, appeal to the commissioner, who, after a hearing held upon notice to the appellant and to the rating organization or insurer, may affirm or reverse such action.
RCW 48.19.310