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2024 Corporate Income Tax Forms

 

Name Instructions Description
IL-1120

PDF

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 PDF Replacement Tax Investment Credits
IL-2220 PDF Computation of Penalties for Businesses
IL-4562

PDF

Special Depreciation
Schedule INL PDF Illinois Net Loss Adjustments for Cooperatives and REMIC Owners
Schedule INS PDF Tax for Foreign Insurers
Schedule J PDF Foreign Dividends
Schedule M PDF Other Additions and Subtractions (for businesses)
Schedule NB PDF Nonbusiness Income
Schedule NLD PDF Illinois Net Loss Deduction
Schedule UB
PDF Combined Apportionment for Unitary Business Group
Schedule UB/INS PDF Tax for a Unitary Business Group with Foreign Insurer Members
Schedule UB/NLD PDF Unitary Illinois Net Loss Deduction
Schedule 80/20 PDF 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

PDF

Income Tax Credits (for corporations and fiduciaries)
Schedule 1299-I  

Income Tax Credits Information and Worksheets

Updated 03/25/2025 - Taxpayers claiming the REV Illinois Investment Credit or MICRO Investment Credit are now required to attach a copy of their worksheet rather than a DCEO certificate.

Schedule 4255

PDF

 
Subgroup Schedule (UB) PDF
Subgroup Schedule