§ 49-04-07 — Unreasonable preferences or advantages prohibited

No public utility shall make or give any undue or unreasonable preference or advantage to
any particular person, company, firm, corporation, limited liability company, or locality, or to any
particular character of service in any respect whatsoever, nor subject any particular person, firm,
corporation, limited liability company, company, or locality, or any particular character of service
to any undue or unreasonable prejudice or disadvantage in any respect. No public utility
corporation, directly or indirectly, by any special rate, rebate, drawback, or other device or
method, shall charge, demand, collect, or receive from any person, firm, corporation, or limited
liability company a greater or less compensation for any service rendered or to be rendered
than it charges, demands, collects, or receives from any other person, firm, corporation, or
limited liability company for doing a like and contemporaneous service under the same or
substantially similar circumstances and conditions. Nothing in this chapter shall prohibit a public
utility from entering into any reasonable agreement with its customers, consumers, or
employees or from providing for a sliding scale of charges, unless the same is prohibited by the
terms of the franchise or permit under which such public utility is operated. No such agreement
or sliding scale shall be lawful unless and until the same shall be filed with and approved by the
commission.