Conn. Gen. Stat. § 1-1b: Payment by bank treasurer's or cashier's check in lieu of certified check.

(a) Any payment which is required by any state statute or municipal ordinance or by any regulation of any state, municipal or other public authority to be made by certified check may be made by bank treasurer's or cashier's check with the same effect as though a certified check had been used.

(b) When the terms of any contract entered into in this state require payment by certified check, unless the contrary is expressly stated, “certified check” shall be construed to include any bank treasurer's or cashier's check.