13 Pa.C.S. § 9340: Effectiveness of right of recoupment or set-off against deposit account.

(a) Exercise of recoupment or set-off.--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) Recoupment or set-off not affected by security interest.--Except as otherwise provided in subsection (c), the application of this division 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) When set-off ineffective.--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 section 9104(a)(3) (relating to requirements for control) if the set-off is based on a claim against the debtor.