Illinois Statutes Chapter 20. Executive Branch § 2510/2510-25. Audit performance and review

(a) Upon the Department's designation of the agreed-upon procedures to be followed by a practitioner in a certified audit, the qualified practitioner shall perform the engagement and shall timely submit a completed report to the Department. The report shall affirm completion of the agreed-upon procedures and shall provide any required disclosures.

(b) The Department shall review the report of the certified audit and shall accept it when it is determined to be complete. Once the report is accepted by the Department, the Department shall issue a notice of proposed assessment reflecting the determination of any additional liability reflected in the report and shall provide the taxpayer with all the normal payment, protest, and appeal rights with respect to the liability, including the right to a review by the Informal Conference Board. In cases where the report indicates an overpayment has been made, the taxpayer shall submit a properly executed claim for refund to the Department. Otherwise, the certified audit report is a final and conclusive determination with respect to the tax and period covered. No additional assessment may be made by the Department for the specific taxes and period referenced in the report, except upon a showing of fraud or material misrepresentation. This determination shall not prevent the Department from collecting liabilities not covered by the report or from conducting an audit or investigation and making an assessment for additional tax, penalty, or interest for any tax or period not covered by the report.