What if I need to correct or change my Form IL-1120?

If you need to correct or change your return after it has been filed you must file Form IL-1120-X, Amended Corporation Income and Replacement Tax Return, for the appropriate tax year. Any correction made may cause a recalculation of penalties and interest. For more information refer to the IL-1120-X Instructions for the tax year you wish to amend. Click the following links for the current year amended form and instructions:

If you have additional inquiries, you may submit them to the Questions, Comments, or Request form.