Section 810 ILCS 5/4-405 - Death or incompetence of customer(a) A payor or collecting bank's authority to accept, pay, or collect an item or to account for proceeds of its collection, if otherwise effective, is not rendered ineffective by incompetence of a customer of either bank existing at the time the item is issued or its collection is undertaken if the bank does not know of an adjudication of incompetence. Neither death nor incompetence of a customer revokes the authority to accept, pay, collect, or account until the bank knows of the fact of death or of an adjudication of incompetence and has reasonable opportunity to act on it.(b) Even with knowledge, a bank may for 10 days after the date of death pay or certify checks drawn on or before that date unless ordered to stop payment by a person claiming an interest in the account.