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Freedom Of Information

What is FOIA?

FOIA is an acronym for Freedom of Information Act.  Under the Illinois Freedom of Information Act (5 ILCS 140/1, et seq.), records in the possession of public agencies may be accessed by the public upon written request.  Pursuant to 5 ILCS 140/2(c), "public records" means all records, reports, forms, writings, letters, memoranda, books, papers, maps, photographs, cards, tapes, recordings, electronic data processing records, recorded information and all other documentary materials, regardless of physical form or characteristics, having been prepared, or having been or being used, received, possessed or under the control of any public body.  Records that are not subject to release under FOIA include confidential taxpayer and tax return information. 

How Do I Submit a FOIA Request?

FOIA requests must be submitted in writing. 

Requests for information must be submitted to:


Phone: 217 782-0985
Fax: 217 524-3402

You may use Form FOIA-1, Freedom of Information Act Request, to request information or provide your own document containing the same information.

The requestor should clearly describe the information being sought.  The request should include full contact information for the requestor, including name, organization, mailing address, fax number, and daytime telephone number. 

All requests are processed in the order in which they are received.  The department will respond within five (5) business days of receipt of the request.  An extension of five (5) business days is allowed with written notification to the requester.

Department Overview

The Illinois Department of Revenue (IDOR) is the tax collection agency for the State of Illinois and also administers a number of taxes imposed by local governments.  The $67.6 billion collected by the department in FY 23 accounts for virtually all of Illinois' own source revenue and is used to provide public safety, health, educational and human services to Illinois citizens. IDOR also has oversight responsibilities involving the nearly $33.8 billion local property tax system.

IDOR's operations are divided into six primary areas: Account Processing, Taxpayer Services, Tax Enforcement and Collections, Audit Bureau, Legal Services, and Administrative Services.  The taxes collected come from three key sources: (1) Illinois Income Tax; (2) Retailers' Occupation Tax and Use Tax (commonly referred to as sales tax); and (3) excise taxes, including taxes on liquor, cigarettes, public utilities, hotel occupancy, and motor fuel. The department's central office is located in Springfield, with five additional regional offices, including an office location in downtown Chicago.

IDOR processes approximately 6.2 million individual income tax returns and 2.1 million business income tax and withholding income tax returns annually. Approximately 66% filing individual income tax returns for the 2022 filing period filed in 2023 received refunds. An estimated 91% of all individual income tax returns are now filed electronically.

Along with its state and local tax collection responsibilities, the department has general oversight responsibilities for Illinois local governments' property tax system. IDOR issues county equalization factors to assure uniform property assessment levels throughout the state and assists local assessing officials with their property tax responsibilities.

IDOR has approximately 1,300 employees in its overall operation.



This website information concerning the FOIA is being provided as required by Section 4 of the Act (5 ILCS 140/4). This website information is subject to revisions and updates.