Utah Code § 54-3-9
Nothing in this title shall be taken to prohibit a corporation or person engaged in the production, generation, transmission, or furnishing of heat, light, water or power, or telegraph or telephone service, from establishing a sliding scale of charges, provided a schedule showing such scale of charges shall first have been filed with the commission and the rates set out therein are approved by it. Nothing in this title shall be taken to prohibit any such corporation or person from entering into an arrangement for a fixed period for the automatic adjustment of charges for heat, light, water or power, or telegraph or telephone service, in relation to the dividends to be paid to stockholders of such corporation or the profit to be realized by such person, provided a schedule showing the scale of charges under such arrangement shall first have been filed with the commission and each rate set out therein is approved by it. Nothing in this section shall prevent the commission from revoking its approval at any time and fixing other rates and charges for the product or commodity or service, as authorized by this title.
Utah Code § 54-3-9