235 ILCS 5/8-9
All information received by the Department from returns filed under this Act, or from any investigation conducted under this Act, shall be confidential, except for official purposes, and any person who divulges any such information in any manner, except in accordance with a proper judicial order or as otherwise provided by law, shall be guilty of a Class B misdemeanor.
Nothing in this Act prevents the Director of Revenue from publishing or making available to the public the names and addresses of persons filing returns under this Act, or reasonable statistics concerning the operation of the tax by grouping the contents of returns so that the information in any individual return is not disclosed.
Nothing in this Act prevents the Director of Revenue from divulging to the United States Government or the government of any other state, or any officer or agency thereof, for exclusively official purposes, information received by the Department in administering this Act, provided that such other governmental agency agrees to divulge requested tax information to the Department.
The furnishing upon request of information obtained by the Department from returns filed under this Act or investigations conducted under this Act to the Illinois Liquor Control Commission for official use is deemed to be an official purpose within the meaning of this Section.
The furnishing upon request of the Auditor General, or his authorized agents, for official use, of returns filed and information related thereto under this Act is deemed to be an official purpose within the meaning of this Section.
The furnishing of financial information to a home rule unit with a population in excess of 2,000,000 that has imposed a tax similar to that imposed by this Act under its home rule powers, upon request of the Chief Executive of the home rule unit, is an official purpose within the meaning of this Section, provided the home rule unit agrees in writing to the requirements of this Section. Information so provided is subject to all confidentiality provisions of this Section. The written agreement shall provide for reciprocity, limitations on access, disclosure, and procedures for requesting information.
Nothing contained in this Act shall prevent the Director from divulging information to any person pursuant to a request or authorization made by the taxpayer or by an authorized representative of the taxpayer.
235 ILCS 5/8-9