Agencies
Services
2025 Corporate Income Tax Forms
| Name | Instructions | Description |
|---|---|---|
| IL-1120 | Corporation Income and Replacement Tax Return | |
| IL-1120-V | Payment Voucher for Corporation Income and Replacement Tax To make a return or extension payment, use this voucher and Appendix A of Form IL-1120 Instructions. To make an estimated payment, use this voucher and Appendix B of Form IL-1120 Instructions. Important: Ensure the proper month and year of the filing period you wish to make a payment for is entered on the "Tax year ending" lines of the voucher. |
|
| IL-1120-X |
PDF |
Amended Corporation Income and Replacement Tax Return |
| IL-1120-X-V | Payment Voucher for Amended Corporation Income and Replacement Tax Important: Ensure the proper month and year of the filing period you wish to make a payment for is entered on the "Tax year ending" lines of the voucher. |
|
| IL-477 | Replacement Tax Investment Credits | |
| IL-2220 | Computation of Penalties for Businesses |
|
| IL-4562 | HTML | PDF | Special Depreciation |
| Schedule INL | Illinois Net Loss Adjustments for Cooperatives and REMIC Owners | |
| Schedule INS | Tax for Foreign Insurers | |
| Schedule J | Foreign Dividends |
|
| Schedule M | Other Additions and Subtractions (for businesses) |
|
| Schedule NB | Nonbusiness Income | |
| Schedule NLD | Illinois Net Loss Deduction | |
| Schedule UB |
Combined Apportionment for Unitary Business Group 03/05/2026 - The instructions were updated to provide additional information for unitary groups with members not taxable in Illinois, including the addition of an Allocation Worksheet used to calculate the correct apportionment amounts for the Illinois taxable members of the unitary business group. |
|
| Schedule UB/INS | Tax for a Unitary Business Group with Foreign Insurer Members | |
| Schedule UB/NLD | Unitary Illinois Net Loss Deduction | |
| Schedule 80/20 | Related-Party Expenses | |
| Schedule 1299-B | PDF |
River Edge Redevelopment Zone or Foreign Trade Zone (or sub-zone) Subtractions (for corporations and fiduciaries) |
| Schedule 1299-D | Income Tax Credits (for corporations and fiduciaries) | |
| Schedule 1299-I | HTML | PDF | Income Tax Credits Information and Worksheets |
| Schedule 4255 | HTML | PDF | Recapture of Investment Credits |
| Subgroup Schedule (UB) | PDF |
Subgroup Schedule 03/05/2026 - The instructions were updated to provide additional information for unitary groups with subgroup members not taxable in Illinois. |