Wash. Rev. Code § 80.28.080
(1)
(a) Except as provided otherwise in this subsection, no gas company, electrical company, wastewater company, water company, or thermal energy company may charge, demand, collect or receive a greater or less or different compensation for any service rendered or to be rendered than the rates and charges applicable to such service as specified in its schedule filed and in effect at the time, nor may any such company directly or indirectly refund or remit in any manner or by any device any portion of the rates or charges so specified, or furnish its product at free or reduced rates except to its employees and their families, and its officers, attorneys, and agents; to hospitals, charitable and eleemosynary institutions and persons engaged in charitable and eleemosynary work; to indigent and destitute persons; to national homes or state homes for disabled volunteer soldiers and soldiers' and sailors' homes. For the purposes of this subsection (1):
[ 2025 c 263 s 14; 2011 c 214 s 17; 1985 c 427 s 2; 1973 1st ex.s. c 154 s 116; 1961 c 14 s 80.28.080. Prior: 1911 c 117 s 29; RRS s 10365.]
Findings—Purpose—Limitation of chapter—Effective date—2011 c 214: See notes following RCW 80.04.010.
Severability—1973 1st ex.s. c 154: See note following RCW 2.12.030.