(50 ILCS 355/10-40)
    Sec. 10-40. 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 in the form and manner required by the Department and professional standards. 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 by the qualified practitioner. Once the report is accepted by the Department, the Department shall provide the taxpayer with all the normal payment, protest, and appeal rights with respect to any liability reflected in the report, including the right to a review by the Informal Conference Board. In cases in which the report indicates an overpayment has been made, the taxpayer shall submit a properly executed claim for credit or 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.
    (c) Any assessment issued by the Department under this Act is subject to the statute of limitations for assessments under the Retailers' Occupation Tax Act, the Use Tax Act, the Service Occupation Tax Act, the Service Use Tax Act, and any local retailers' or service occupation tax, as appropriate, and local taxes collected on assessments issued shall be allocated to units of local government for the full period of the statute of limitations in accordance with those Acts and any applicable local retailers' or service occupation tax Act. The Department shall provide notice in writing to the municipality or county and the third party, if applicable, of any audit findings, determinations, or collections once finalized, but limited to the amount of additional liability, if any, for distribution to the municipality or county as part of the municipality's or county's share of the State Retailers' Occupation Tax or Service Occupation Tax or under the municipality's or county's locally imposed retailer's or service occupation tax.
    Claims for credit or refund filed by taxpayers under this Act are subject to the statute of limitations under the Retailers' Occupation Tax Act, the Use Tax Act, the Service Occupation Tax Act, the Service Use Tax Act, and any local retailers' or service occupation tax Act, as appropriate, and any credit or refund of local taxes allowed to the taxpayer shall be de-allocated from units of local government for the full period of the statute of limitations in accordance with those Acts and any applicable local retailers' or service occupation tax Act.
    If a reallocation of tax from one unit of local government to another occurs as a result of an amended return filed by a taxpayer or an audit of a taxpayer, the Department shall make the reallocation for the full period of the statute of limitations under the Retailers' Occupation Tax Act, the Use Tax Act, the Service Occupation Tax Act, the Service Use Tax Act, and any applicable local retailer's or service occupation tax Act.
    With respect to misallocations discovered under this Act, the Department shall increase or decrease the amount allocated to a unit of local government by an amount necessary to offset any misallocation of previous disbursements. The offset amount shall be the amount erroneously disbursed within the previous 6 months from the time a misallocation is discovered.
    (d) Under no circumstances may a person, including a municipality or county or third party, other than the person audited and his or her attorney, have any right to participate in an appeal or other proceeding regarding the audit, participate in settlement negotiations, challenge the validity of any settlement between the Department and any person, or review any materials, other than financial information as otherwise provided in this Act, that are subject to the confidentiality provisions of the underlying tax Act. In addition, the Department's determination of whether to audit a taxpayer or the result of the audit creates no justiciable cause of action, and any adjudication related to this program is limited to the taxpayer's rights in an administrative hearing held by the Department, an administrative hearing held by the Illinois Independent Tax Tribunal, or related to payments made under protest as provided in Section 2a.1 of the State Officers and Employees Money Disposition Act, as appropriate.
(Source: P.A. 101-628, eff. 6-1-20; 102-40, eff. 6-25-21.)