476.5 Adherence to schedules. No public utility subject to rate regulation shall directly or indirectly charge a greater or less compensation for its services than that prescribed in its tariffs, and no such public utility shall make or grant any unreasonable preferences or advantages as to rates or services to any person or subject any person to any unreasonable prejudice or disadvantage. [C66, 71, 73, 75, §490A.5; C77, 79, 81, §476.5] 2014 Acts, ch 1099, §5
Iowa Legal Code