Oregon Revised Statutes Utility Regulation § 756.500

(1) Any person may file a complaint before the Public Utility Commission, or the commission may, on the commission's own initiative, file such complaint. The complaint shall be against any person whose business or activities are regulated by some one or more of the statutes, jurisdiction for the enforcement or regulation of which is conferred upon the commission. The person filing the complaint shall be known as the complainant and the person against whom the complaint is filed shall be known as the defendant.

(2) It is not necessary that a complainant have a pecuniary interest in the matter in controversy or in the matter complained of, but the commission shall not grant any order of reparation to any person not a party to the proceedings in which such reparation order is made.

(3) The complaint shall state all grounds of complaint on which the complainant seeks relief or the violation of any law claimed to have been committed by the defendant, and the prayer of the complaint shall pray for the relief to which the complainant claims the complainant is entitled.

(4) The complaint may, at any time before the completion of taking of evidence, be amended by order of the commission. However, if a charge not contained in the original complaint or a prior amended complaint is sought to be made by any such amendment, the defendant shall be given a reasonable time to investigate the new charge and answer the amended complaint. The final hearing shall, if necessary, be continued until some date after the defendant has had a reasonable time to investigate and be prepared to meet the amended complaint.

(5) Notwithstanding subsection (1) of this section, any public utility or telecommunications utility may make complaint as to any matter affecting its own rates or service with like effect as though made by any other person, by filing an application, petition or complaint with the commission.