Wash. Rev. Code § 43.23.255
Except as otherwise specified by law, any due and payable assessment levied under the authority of the director or his or her designee in such specified amount as may be determined by the department shall constitute a personal debt of every person so assessed or who otherwise owes the same, and the same shall be due and payable to the department when payment is called for by the department. In the event any person fails to pay the department the full amount of such assessment or such other sum on or before the date due, the department may, and is hereby authorized to, add to such unpaid assessment or other sum an amount not exceeding ten percent of the same to defray the cost of enforcing the collecting of the same. In the event of failure of such person or persons to pay any such due and payable assessment or other sum, the department may bring a civil action against such person or persons in a court of competent jurisdiction for the collections thereof, including all costs and reasonable attorneys' fees together with the above specified ten percent, and such action shall be tried and judgment rendered as in any other cause of action for debt due and payable.
RCW 43.23.255
Effective date-1995 c 374 ss 1-47, 50-53, and 59-68: See note following RCW 15.36.012.