Wash. Rev. Code § 11.120.150
(1) The legal duties imposed on a fiduciary charged with managing tangible property apply to the management of digital assets, including:
(2) A fiduciary's or designated recipient's authority with respect to a digital asset of a user:
(5) A fiduciary with authority over the tangible, personal property of a decedent, incapacitated person, principal, or settlor:
(7) A fiduciary of a user may request a custodian to terminate the user's account. A request for termination must be in writing, in either physical or electronic form, and accompanied by:
(c) If requested by the custodian:
[ 2016 c 140 s 15.]