4.50 G. Illinois Form IL-941: Employer's Quarterly Illinois Withholding Tax Return

Employers must file Form IL-941 to report Illinois income tax withheld each calendar quarter. This form applies only to Illinois income tax withholding and is due by the last day of the month following the calendar quarter.

Instructions for completing the IL-941 appear on the form. Payment of any undeposited taxes (normally each quarter) is due with the form.

Download and Print withholding forms for Illinois income tax.