Illinois Statutes Chapter 220. Utilities § 5/15-508. Statute of limitations for charges

(a) Collection actions. Actions to collect charges under lawfully applicable rates must be instituted within 3 years after rendition of the service.

(b) Reparations or overcharge proceedings. Petitions seeking reparations or repayment of overcharges must be filed with the Commission within 3 years after rendition of the service, and an action seeking judicial enforcement of a Commission order awarding reparations must be instituted within one year after issuance of such order. Where an action seeking judicial review of a Commission order awarding reparations is filed, the time preceding final adjudication of the action shall be excluded in computing the time for instituting the action seeking judicial enforcement of the Commission order.