Wash. Rev. Code § 48.18.360
Subject to the terms of the policy relating to its assignment, life insurance policies, other than industrial or group life insurance policies, and disability policies providing benefits for accidental death, whether such policies were heretofore or are hereafter issued, and under the terms of which the beneficiary may be changed upon the sole request of the insured, may be assigned either by pledge or transfer of title, by an assignment executed by the insured alone and delivered to the insurer, whether or not the pledgee or assignee is the insurer. Industrial life insurance policies may be made assignable only to a bank or trust company. Any such assignment shall entitle the insurer to deal with the assignee as the owner or pledgee of the policy in accordance with the terms of the assignment, until the insurer has received at its home office written notice of termination of the assignment or pledge, or written notice by or on behalf of some other person claiming some interest in the policy in conflict with the assignment.
RCW 48.18.360