Wash. Rev. Code § 84.56.335
(2) Upon notification by the assessor, the county treasurer must remove from the tax rolls any outstanding taxes, as well as interest and penalties, on a manufactured/mobile home or park model trailer if the landlord of a manufactured/mobile home park:
(a) Submits a signed affidavit to the assessor indicating that the landlord has taken ownership of the manufactured/mobile home or park model trailer with the intent to resell or rent after:
[ 2013 c 198 s 1.]