Complete the on-line application for free child support services if you live in Illinois and the dependent child(ren) lives with you. The Child Support Application is available for download in Portable Document Format (PDF).It can then be filled out on your computer. Download and complete Divorce, Child Support, and Maintenance forms from the Illinois Office of the Courts. The Office of the Clerk of the Circuit Court is a participant in the federal and state funded child support collection and enforcement services. Fill out and sign the forms listed below. Make at least three copies of each form. Note: This form also applies to some tax benefits, including the child tax credit, additional child tax credit, and credit for other dependents. The ILSDU is the payment processing center for Illinois child support payments. This method is based on both parents' income and the number of children included in the child support order using the Illinois child support guidelines.