Washington Revised Code Title 50. Unemployment Compensation § 50.24.220. Client employer liability--Collection

(1) The client employer of a professional employer organization is liable for the payment of any taxes, interest, or penalties due.

(2) The professional employer organization may collect and pay taxes due to the department for unemployment insurance coverage from its client employers in accordance with its professional employer agreement. If such payments have been made to the professional employer organization by the client employer, the department shall first attempt to collect the contributions due from the professional employer organization.

(3) To collect any contributions, penalties, or interest due to the department from the professional employer organization, the department must follow the procedures contained in chapter 50.24 RCW. If the amount of contributions, interest, or penalties assessed by the commissioner pursuant to chapter 50.24 RCW is not paid by the professional employer organization within ten days, then the commissioner may follow the collection procedures in chapter 50.24 RCW. After the ten-day period, if the professional employer organization has not paid the total amount owing, the commissioner may also pursue the client employer to collect what is owed using the procedures contained in chapter 50.24 RCW.