2021 Corporate Income Tax Forms

IL-1120 Instructions Corporation Income and Replacement Tax Return

Payment Voucher for 2021 Corporation Income and Replacement Tax (Use this voucher and Appendix A of Form IL-1120 Instructions to make a 2021 return or extension  payment)

2022-IL-1120-VPayment Voucher for 2022 Corporation Income and Replacement Tax (Use this voucher and Appendix B of Form IL-1120 Instructions to make 2022 estimated payments)
​Amended Corporation Income and Replacement Tax Return
IL-1120-X-V  Payment Voucher for Amended Corporation Income and Replacement Tax
IL-477 Instructions Replacement Tax Investment Credits
IL-2220 Instructions Computation of Penalties for Businesses
Instructions Special Depreciation
Schedule INL Instructions Illinois Net Loss Adjustments for Cooperatives and REMIC Owners
Schedule INS Instructions Tax for Foreign Insurers
Schedule J Instructions Foreign Dividends
Schedule M Instructions Other Additions and Subtractions (for businesses)
Schedule NB Instructions Nonbusiness Income
Schedule UB Instructions Combined Apportionment for Unitary Business Group
Schedule UB/INS Instructions Tax for a Unitary Business Group with Foreign Insurer Members
Schedule 80/20 Instructions Related-Party Expenses
Schedule 1299-B Instructions River Edge Redevelopment Zone or Foreign Trade Zone (or sub-zone) Subtractions (for corporations and fiduciaries)
Schedule 1299-D Instructions Income Tax Credits (for corporations and fiduciaries)
​Schedule 1299-I
​Income Tax Credits Information and Worksheets
Schedule 4255 Instructions Recapture of Investment Tax Credits
Subgroup Schedule (UB) Instructions
Subgroup Schedule