Generally, pension and annuity payments are subject to Federal income tax withholding. A copy of the income withholding notice together with a proof of service on the other payor shall be filed with the Clerk of the Circuit Court.Use this form to let the other parent's employer know to withhold child support from paychecks. IMRF will not withhold state income tax for any state outside of Illinois. The individual commutes daily to their job in Illinois. Want to check on the status of your individual Illinois income tax refund? Just provide us with your Social Security number, first and last name. File your Illinois income tax return. All tax brackets are supported. The Illinois Department of Revenue allows you to electronically pay your current or estimated income taxes, even before filing or with an extension.