2005 Washington Revised Code RCW 7.28.110: Substitution of landlord in action against tenant.

A defendant who is in actual possession may, for answer, plead that he is in possession only as a tenant of another, naming him and his place of residence, and thereupon the landlord, if he applies therefor, shall be made defendant in place of the tenant, and the action shall proceed in all respects as if originally commenced against him. If the landlord does not apply to be made defendant within the time the tenant is allowed to answer, thereafter he shall not be allowed to, but he shall be made defendant if the plaintiff require it. If the landlord be made defendant on motion of the plaintiff he shall be required to appear and answer within ten days from notice of the pendency of the action and the order making him defendant, or such further notice as the court or judge thereof may prescribe.

[Code 1881 § 537; 1877 p 112 § 541; 1869 p 128 § 489; RRS § 792.]