Illinois Department of Revenue Tax Forms

Individual Tax Forms	Corporate Tax Forms	Partnership Tax Forms	E-File
S Corporation Tax Forms	Fiduciary Tax Forms

In the state of Illinois tax preparation professionals who are approved to file electronically will receive the same state privileges to file state taxes without any further required approval process.

Tax Brackets in Illinois

Illinois has one marginal (flat) tax bracket of 5.00% for all state individual and married filers.

Extensions

The state of Illinois will automatically extend a six month extension to calendar year filers until October 15^th. However, in order to avoid penalties and interests you must pay any tentative taxes that are due by the original due date of your return. 

Extension Mailing Address

• Illinois Department of Revenue P.O. Box 19005 – Springfield IL 62794-9005

Where to Send a Tax Return

State Return Mailing Address

• Illinois Department of Revenue PO Box 1040 – Galesburg IL 61402-1040

Contact the Department of Revenue

• Website
• Telephone – 1(800) 732-8866

Previous Years

• Individual
• Corporate
• Partnerships
• Estates