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This document research library provides access to electronic versions of many prior documents and forms. Please note that statutes and rules referenced in these documents are not included in this online library; they can be found on the Illinois General Assembly website, ilga.gov.
Current year information is located on the main website, tax.illinois.gov.
What resources are available in the document research library?
- Informational Bulletins issued in prior years
- Tax forms and instructions for prior years
- Legal documents such as letter rulings (private and general) and Administrative Hearings
- Annual reports
- Statistical reports
- and more
The Illinois Department of Revenue Tax Research Library search function allows you to search by keywords or phrases and refine your selection to narrow your search.
Click here to begin your search.
If you are seeking something that does not appear in your search, you may submit an inquiry using the web form or a Freedom of Information Request. If you are having difficulty with this website or have a suggestion for how to make the site better, you may email the Webmaster.
Disclaimer
The documents available in this tax research library are provided for reference and may be superseded. The research library is not a comprehensive collection; however, it includes thousands of files and will change over time based on requests received and other factors. Certain information, such as names and addresses, may be redacted to protect taxpayer privacy.