RCW 50.04.100: Employment.

"Employment," subject only to the other provisions of this title, means personal service, of whatever nature, unlimited by any employment relationship as known to the common law or any other legal relationship, including service in interstate commerce, performed for wages or under any contract calling for the performance of personal services, written or oral, express or implied.

Except as provided by RCW 50.04.145, personal services performed for an employing unit by one or more contractors or subcontractors acting individually or as a partnership, which do not meet the provisions of RCW 50.04.140, shall be considered employment of the employing unit: PROVIDED, HOWEVER, That such contractor or subcontractor shall be an employer under the provisions of this title in respect to personal services performed by individuals for such contractor or subcontractor.