Illinois — Corporation Income and Replacement Tax Return
More about the Illinois Form IL-1120 Tax Return
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File Now with TurboTaxWe last updated Illinois Form IL-1120 in January 2025 from the Illinois Department of Revenue. This form is for income earned in tax year 2024, with tax returns due in April 2025. We will update this page with a new version of the form for 2026 as soon as it is made available by the Illinois government.
Other Illinois Corporate Income Tax Forms:
In addition to information about Illinois' income tax brackets, Tax-Brackets.org provides a total of 76 Illinois income tax forms, as well as many federal income tax forms. Here's a list of some of the most commonly used Illinois tax forms:
| Form Code | Form Name |
|---|---|
| Schedule UB-NLD | Unitary Illinois Net Loss Deduction [OBSOLETE] |
| Form IL-516-B | Pass-through Prepayment [OBSOLETE] |
| Schedule 1299-S | Enterprise Zones, Foreign Trade Zones, and Sub-Zones |
| Form IL-1120 | Corporation Income and Replacement Tax Return |
| Form IL-1041-V | Payment Voucher for Fiduciary Income and Replacement Tax |
View all 76 Illinois Income Tax Forms
Disclaimer: While we do our best to keep Form IL-1120 up to date and complete on Tax-Brackets.org, we cannot be held liable for errors or omissions. Is this form missing or out-of-date? Please let us know so we can fix it!
Tax Form Sources:
- Illinois Department of Revenue ( https://www2.illinois.gov/rev/Pages/default.aspx )
- Department of Revenue Income Tax Forms ( https://www2.illinois.gov/rev/forms/Pages/default.aspx )