Illinois Tax Information 2025
Illinois Income Tax Overview
Illinois uses a flat tax system where all residents pay the same rate regardless of income level. Understanding the state tax system is crucial for proper tax planning and compliance.
Tax Deductions and Credits
Standard Deduction
Illinois offers a standard deduction of $2,425 per exemption for tax year 2025.
Common Tax Credits
- Property Tax Credit
- Earned Income Credit
- Education Expense Credit
- Child and Dependent Care Credit
Filing Requirements
Who Must File
You must file an Illinois income tax return if you:
- Are an Illinois resident who must file a federal income tax return
- Are a nonresident who earned income in Illinois
- Received income from Illinois sources while a nonresident
Important Tax Deadlines
- April 15, 2025: Individual income tax returns due
- October 15, 2025: Extended filing deadline
- Quarterly Estimated Tax Due Dates: April 15, June 15, September 15, January 15