35 ILCS 630/15
All information received by the Department from returns filed under this Article, or from any investigations conducted under this Article, 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.
Provided, that nothing contained in this Article shall prevent the Director from publishing or making available to the public the names and addresses of retailers or taxpayers filing returns under this Article, or from publishing or making available reasonable statistics concerning the operation of the tax wherein the contents of returns are grouped into aggregates in such a way that the information contained in any individual return shall not be disclosed.
And provided, that nothing contained in this Article shall prevent the Director from making available 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 the administration of this Article, if such other governmental agency agrees to divulge requested tax information to the Department.
The furnishing upon request of the Auditor General, or his authorized agents, for official use, of returns filed and information related thereto under this Article is deemed to be an official purpose within the meaning of this Section.
The furnishing of financial information to a municipality that has imposed a tax under the Simplified Municipal Telecommunications Tax Act, upon request of the chief executive thereof, is an official purpose within the meaning of this Section, provided that the municipality agrees in writing to the requirements of this Section. Information so provided shall be subject to all confidentiality provisions of this Section. The written agreement shall provide for reciprocity, limitations on access, disclosure, and procedures for requesting information.
The Director shall make available for public inspection in the Department's principal office and for publication, at cost, administrative decisions issued on or after January 1, 1995. These decisions are to be made available in a manner so that the following taxpayer information is not disclosed:
The Director shall determine the appropriate extent of the deletions allowed in paragraph (2). In the event the taxpayer does not submit deletions, the Director shall make only the deletions specified in paragraph (1).
The Director shall make available for public inspection and publication an administrative decision within 180 days after the issuance of the administrative decision. The term "administrative decision" has the same meaning as defined in Section 3-101 of Article III of the Code of Civil Procedure. Costs collected under this Section shall be paid into the Tax Compliance and Administration Fund.
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.
35 ILCS 630/15