30 ILCS 210/10.1
Except where prohibited by federal law or regulation, in the case of any liability referred to a collection agency on or after July 1, 2010, any fee charged to the State by the collection agency (i) may not exceed 25% for a first placement of the underlying liability referred to the collection agency unless the liability is for a tax debt, (ii) is considered an additional liability owed to the State, (iii) is immediately subject to all collection procedures applicable to the liability referred to the collection agency, and (iv) must be separately stated in any statement or notice of the liability issued by the collection agency to the debtor. The fee limitations of this Section do not apply to a second, third, or subsequent placement or to litigation activities.
30 ILCS 210/10.1