305 ILCS 5/10-17.5
The Illinois Department may provide by rule for certification to the Comptroller of past due support owed by responsible relatives under a support order entered by a court or administrative body of this or any other State on behalf of resident or non-resident persons. The purpose of certification shall be to intercept state income tax refunds and other payments due such relatives in order to satisfy such past due support, in whole or in part, whether or not such support is owed to the State. The rule shall provide for notice to and an opportunity to be heard by the responsible relative and any joint payee affected and any final administrative decision rendered by the Department shall be reviewed only under and in accordance with the Administrative Review Law. In any case where a state income tax refund is intercepted wrongfully or erroneously, the Department shall pay to such relative and any joint payee affected the amount of the refund plus interest, if any, on such amount at the rate of 9% per annum (or at such adjusted rate as is established under Section 6621(b) of the Internal Revenue Code). Interest shall be calculated from the date the Department receives the refund or from 60 days following the date the Department receives a request to be heard, whichever is later, until the date of payment to such relative and joint payee.
305 ILCS 5/10-17.5