30 ILCS 435/20
(a) If authorized in the contract between a State agency and a service provider, whenever the service provider is required to replenish the reserve fund established under a covered bond issue, the trustee of the reserve fund shall certify to the affected State agency the amount required to meet the service provider's obligation. The certification must specifically identify:
(5) the amount that the service provider is required to pay into the reserve fund.
The certification must also include provisions requiring a refund to the State agency, or to the service provider if so directed by the State agency, of any surplus amount received by the bond trustee from the State agency.
(Source: P.A. 88-117.)