ORS 757.225: Utilities required to collect for their services in accordance with schedules.

No public utility shall charge, demand, collect or receive a greater or less compensation for any service performed by it within the state, or for any service in connection therewith, than is specified in printed rate schedules as may at the time be in force, or demand, collect or receive any rate not specified in such schedule. The rates named therein are the lawful rates until they are changed as provided in ORS 757.210 to 757.220.