Section 31.21.01.203 - BILLING ERRORS, BILLING UNDER INCORRECT RATES, OR FAILURE TO BILL FOR SERVICE01.Billing Errors -- Failure to Bill. Whenever the billing for utility service was not accurately determined for reasons such as a meter malfunction or failure, incorrect installation or programming of metering equipment, or errors in preparation of bills, the utility will prepare a corrected billing. If the utility has failed to bill a customer for service provided, the utility will prepare a bill for the period during which service was provided and the customer was not billed. At its discretion, the utility may waive rebilling for undercharges.02.Billing Under Incorrect Rates. A customer has been billed under an incorrect rate if the customer was billed under a rate for which the customer was not eligible or the customer, who is eligible for billing under more than one (1) rate, was billed under a rate contrary to the customer's election or the election was made based upon erroneous information provided by the utility. If a customer is billed under an incorrect rate, the utility must recalculate the customer's past bills and correctly calculate future bills based on the appropriate rate. The utility is not required to adjust bills when it has acted in good faith based upon information provided by the customer.03.Rebilling Time Period. a. If the time when the billing error, billing under incorrect rates, or failure to bill (collectively referred to as "billing problem") began cannot be reasonably determined to have occurred within a specific period, the corrected billings will not exceed the most recent six (6) months before the discovery of the billing problem.b. If the time when the billing problem began can be reasonably determined and the utility determines the customer was overcharged, the corrected billings will go back to that time, but not to exceed three (3) years from the time the billing problem occurred as provided by Section 61-642, Idaho Code.c. If the time when the billing problem can be reasonably determined and the utility determines the customer was undercharged, the utility may rebill for a period of six (6) months unless a reasonable person should have known of the inaccurate billing, in which case the rebilling may be extended for a period not to exceed three (3) years. Utilities must implement procedures designed to monitor and identify customers who have not been billed or who have been inaccurately billed.04.Refunds. The utility will promptly recalculate the refund amounts overpaid by the customer and issue a credit within two (2) billing cycles. Any remaining credit balance will be credited against future bills unless the customer, after notice from the utility, requests a refund. The utility will advise the customer of the option to have any remaining credit balance exceeding twenty-five dollars ($25) refunded.05.Additional Payments. The utility will promptly prepare a corrected billing for a customer who has been undercharged indicating the amount owed to the utility. An unbilled or undercharged customer must be given the opportunity to make payment arrangements under Rule 313 on the amount due. At the customer's option, the term of the payment arrangement may extend for the length of time that the underbilling accrued or the customer was not billed.Idaho Admin. Code r. 31.21.01.203