Ill. Admin. Code tit. 83, § 525.70 – Annual Reconciliation

a) In conjunction with a docketed reconciliation proceeding, the utility shall file with the Commission an annual reconciliation statement, which shall be certified by the utility's independent public accountants and verified by an officer of the utility. This statement shall show the difference between the following:
1. 1) the costs recoverable through the Gas Charge(s) during the reconciliation year, as adjusted by Factor A and Factor O, and
2. 2) the revenues arising through the application of the Gas Charge(s) to applicable therms during the reconciliation year.
b) If, after hearing, the Commission finds that the utility has not shown all costs to be prudently incurred or has made errors in its reconciliation statement for such reconciliation year, the difference determined by the Commission shall be refunded or recovered, as appropriate, under the Ordered Reconciliation Factor (Factor O), along with any interest or other carrying charge authorized by the Commission.