Tariffs are public documents, written by regulated entities and approved by the regulatory commission, that detail a utility’s rates, rules, service territories, and terms of service. Tariffs are written in accordance with the final decision of the regulatory body. Since decisions are often open to interpretation, tariffs must be approved by the regulatory body before they are legal. In general, tariffs include the following:
Tariffs that have been approved by a regulatory commission are binding legal documents that constitute the contract between the regulated entity and its customers. A regulated entity cannot change its tariffs or fail to follow any provision in its tariffs in any way without approval from the regulatory agency. Copies of an entity's tariffs can be found on the company’s website.