Wash. Rev. Code § 48.12.425
(2)
(a) Credit for reinsurance shall not be granted under this section unless the form of the trust and any amendments to the trust have been approved by:
(3) The following requirements apply to the following categories of assuming insurer:
(c)
(i) In the case of a group including incorporated and individual unincorporated underwriters:
(d) In the case of a group of incorporated underwriters under common administration, the group must:
[ 2015 c 63 s 6.]