Illinois State Income Tax Revenue & Refunds

Illinois residents, partial-year residents and nonresidents who earn income in the state have to file IL taxes. The IL income tax rate is 3.75%, which is lower than the national average. Recently total state tax revenue exceeded $36 billion. This is considerably higher than the nation's median range.

Filing An Amended Tax Return

If an error is made and discovered on a tax form, it is important to file an amended return. Use Form IL-1040X instead of IL-1040 to file an amendment. When finished, mail the form and any required payment to Illinois Department of Revenue at:

Requesting A Tax Extension


Taxpayers requesting a tax extension should send a copy of their IRS tax extension along with their tax forms to either of the applicable addresses in the first paragraph of this guide.

Where To Send Illinois Tax Returns & Payments


When mailing tax forms with payments, send them to:


Taxpayers expecting refunds should also mail returns to the DOR but to the following address instead:

Track A Tax Return Or Refund

To track an Illinois tax refund, visit tax.illinois.gov. Click the "My Refund" link under the box labeled "Individuals." For other questions about tax refunds and returns or amended returns, call 800-732-8866.

Form for Estimated Tax Payments

Taxpayers who are required to make estimated quarterly payments must use Form IL-1040ES and mail it to the Illinois Department of Revenue. Failure to make timely tax payments can results in two different tiers of penalties. The first applies to people who file late or file without paying the tax they owe. The initial penalty amount is the lesser of 2% of the amount owed or $250. The Department of Revenue then sends a notice of nonpayment. If IL taxes are not paid or the return is not filed within 30 days of receiving a notice, an additional fee of the lesser of 2% of the amount due or $250 is added to the initial penalty.

Note: States & U.S. territories may make changes to their tax laws with little notice. We do our best to keep this information up-to-date, but it is provided on an "AS IS" basis. For more see our terms.