Conn. Gen. Stat. § 42a-9-340: Effectiveness of right of recoupment or set-off against deposit account.

(a) Except as otherwise provided in subsection (c), a bank with which a deposit account is maintained may exercise any right of recoupment or set-off against a secured party that holds a security interest in the deposit account.

(b) Except as otherwise provided in subsection (c), the application of this article to a security interest in a deposit account does not affect a right of recoupment or set-off of the secured party as to a deposit account maintained with the secured party.

(c) The exercise by a bank of a set-off against a deposit account is ineffective against a secured party that holds a security interest in the deposit account which is perfected by control under subdivision (3) of subsection (a) of section 42a-9-104 if the set-off is based on a claim against the debtor.