(a) Except as provided in AS 42.05.306, a public utility may not, as to rates, grant an unreasonable preference or advantage to any of its customers or subject a customer to an unreasonable prejudice or disadvantage. A public utility may not establish or maintain an unreasonable difference as to rates, either as between localities or between classes of service. A municipally owned utility may offer uniform or identical rates for a public utility service to customers located in different areas within its certificated service area who receive the same class of service. Any uniform or identical rate shall, upon complaint, be subject to review by the commission and may be set aside if shown to be unreasonable.

(b) A rate charged by a municipality for a public utility service furnished beyond its corporate limits is not considered unjustly discriminatory solely because a different rate is charged for a similar service within its corporate limits.

(c) A public utility may not directly or indirectly refund, rebate or remit in any manner, or by any device, any portion of the rates and charges or charge, demand, or receive a greater or lesser compensation for its services than is specified in its effective tariff. A public utility may not extend to any customer any form of contract, agreement, inducement, privilege, or facility, or apply any rule, regulation, or condition of service except such as are extended or applied to all customers under like circumstances. A public utility may not offer or pay any compensation or consideration or furnish any equipment to secure the installation or adoption of the use of utility service unless it conforms to a tariff approved by the commission, and the compensation, consideration, or equipment is offered to all persons in the same classification using or applying for the public utility service; in determining the reasonableness of such a tariff filed by a public utility the commission shall consider, among other things, evidence of consideration or compensation paid by a competitor, regulated or nonregulated, of the public utility to secure the installation or adoption of the use of the competitor's service.

(d) Nothing in this section prevents a public utility from charging reduced rates to customers transferred to it from a competing utility provided the reduction is an integral part of a contract, arrangement, or plan to eliminate the overlapping of service areas or to minimize duplication of facilities and competition between public utilities.