The extended due date of the Illinois income tax return coincided with the 10/15/18 extended due date for the federal return. So the IL Dept. of Revenue recognizes that taxpayers may have had trouble meeting the deadline. The department announced it will approve requests for abatement of penalties for late filing of any Forms IL-1120, IL-1120-ST, IL-1065 and IL-1041 due to reasonable cause on a case-by-case basis, provided those returns are filed on or before 11/15/18. Requests for abatement should be made after a notice has been received by the taxpayer.