15 ILCS 405/10.08
If any warrant is undeliverable to the payee, it shall be returned to the comptroller, who shall if he determines that the warrant is undeliverable mark the face of the warrant "Cancelled for Redeposit", cancel the warrant and transmit notice to the vouchering agency of such cancellation.
Upon receiving a warrant returned for redeposit, the comptroller may redeposit it with the State Treasurer. Warrants mailed by the comptroller to the payee (or the payee's designated addressee) may be considered undeliverable if returned by the United States Postal Service after attempted delivery or may be remailed once by the comptroller within 30 days of the date of return to a corrected address supplied by the issuing agency except that warrants paying grants to individuals under The Illinois Public Aid Code shall not be remailed. Warrants returned uncashed to the comptroller by any State agency, or by any person other than the payee, may, after inquiry as to its deliverability if the warrant is not void, be treated as an undeliverable warrant under this Section. Warrants returned to the comptroller which he determines to be deliverable or redeliverable shall be mailed by him to the payee or other designated addressee if a reasonable time remains before the warrant shall become void.
15 ILCS 405/10.08