Instructions for Form IL-1120 Corporation Income and Replacement Tax Return - Illinois

Form IL-1120 Corporation Income and Replacement Tax Return - Illinois

This document contains official instructions for Form IL-1120 , Corporation Income and Replacement Tax Return - a form released and collected by the Illinois Department of Revenue. An up-to-date fillable Form IL-1120 is available for download through this link.

FAQ

Q: What is Form IL-1120?
A: Form IL-1120 is the Corporation Income and Replacement Tax Return for businesses in Illinois.

Q: Who is required to file Form IL-1120?
A: Corporations that are required to pay income tax in Illinois must file Form IL-1120.

Q: What is the purpose of Form IL-1120?
A: The purpose of Form IL-1120 is to report a corporation's income and calculate the amount of tax owed to the state of Illinois.

Q: What is the due date for filing Form IL-1120?
A: Form IL-1120 must be filed by the 15th day of the 3rd month following the close of the tax year.

Q: Are there any extensions available for filing Form IL-1120?
A: Yes, corporations can request an extension of time to file Form IL-1120, but any tax owed must still be paid by the original due date.

Q: What penalties or interest may be imposed for late filing of Form IL-1120?
A: Penalties and interest may be imposed for late filing of Form IL-1120, including a penalty for failure to file and a penalty for failure to pay the tax owed.

Q: Are there any special considerations for S corporations filing Form IL-1120?
A: S corporations in Illinois are required to file Form IL-1120-ST, also known as the S Corporation Replacement Tax Return.