Wash. Rev. Code § 19.28.521
No person, firm, or corporation engaging in or conducting or carrying on the business of telecommunications installation shall be entitled to commence or maintain any suit or action in any court of this state pertaining to any such work or business, without alleging and proving that such person, firm or corporation held, at the time of commencing and performing such work, an unexpired, unrevoked, and unsuspended license issued under this subchapter; and no city or town requiring by ordinance or regulation a permit for inspection or installation of such telecommunications installation work, shall issue such permit to any person, firm or corporation not holding such license.
RCW 19.28.521
Severability-2000 c 238: See note following RCW 19.28.301.