MyTax Illinois is a
free online application for electronically filing your Form IL-941 Illinois Withholding Tax Return and Form UI-3/40, Contribution and Wage Report. Follow the instructions on the MyTax Illinois screens and enter your tax information. MyTax Illinois will calculate your return or report and tell you whether or not you have a balance due or are overpaid. At the end of your successful filing, you will be given a confirmation number, which is your proof of filing.
Note: To make your semi-weekly or monthly payments of withholding tax or pay your unemployment insurance tax online, use MyTax Illinois