Illinois Administrative Code
Title 86 - REVENUE
Part 510 - THE PUBLIC UTILITIES REVENUE ACT
Section 510.135 - Books and Records

a) Every taxpayer under the Act shall keep books, records, papers, and other documents which are adequate to reflect the information which such taxpayers are required by Section 2a.2 of the Act to report to the Department by filing annual returns with the Department. For purposes of this Section, "records" means all data maintained by the taxpayer, including data on paper, microfilm, microfiche or any type of machine-sensible data compilation. [35 ILCS 620/7]

b) All books and records and other papers and documents required by the Act to be kept shall be kept in the English language and shall, at all times during business hours of the day, be subject to inspection by the Department or its duly authorized agents and employees. Books and records reflecting kilowatt-hours of electricity distributed during any period with respect to which the Department is authorized to establish liability, as provided in Section 5 of the Act, shall be preserved until the expiration of such period, unless the Department, in writing, authorizes their destruction or disposal at an earlier date. [35 ILCS 620/7]