Conn. Gen. Stat. § 42a-4A-204
Refund of payment and duty of customer to report with respect to unauthorized payment order.
(b) Reasonable time under subsection (a) of this section may be fixed by agreement as stated in subsection (b) of section 42a-1-302 , but the obligation of a receiving bank to refund payment as stated in subsection (a) of this section may not otherwise be varied by agreement.