Ill. Admin. Code tit. 74, § 760.290
a) Subject to the owner interest provisions of Section 15-210 of the Act, a deceased owner cannot indicate interest in his or her property. [765 ILCS 1026/15-201]
e) Sections 15-202 and 15-208 of the Act both provide that when a holder, in the ordinary course of its business, receives notice or an indication of the death of an apparent owner, the holder shall attempt not later than 90 days after receipt of the notice or indication to confirm whether the apparent owner is deceased.