How do I file a correction for the IL-941 return?

You must electronically file Form IL-941-X, Amended Illinois Withholding Income Tax Return, with all required support, if

  • you need to correct amounts you reported on previously filed Forms IL-941 or IL-941-X,
  • you disagree with a change we made on your account, or
  • you are requesting approval of an overpayment for a refund.

If you made an error that requires a Form IL-941-X and you made the same reporting error on your return and your employee’s Form W-2 or payee’s Form 1099 or W-2G, you must also provide your employee or payee with a Form W-2c or corrected Form 1099 or W-2G, and attach copies to your Form IL-941-X. We encourage you to use MyTax Illinois to file and submit this form electronically.

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