Okla. Stat. tit. 12A, § 1-9-340
Oklahoma Code Comment
A banking institution's rights of set-off and recoupment against a deposit account maintained at the institution defeat an existing, perfected security interest in favor of a third-party secured party, except against a secured party that has become the depositary institution's customer of the deposit account (see section 9-104 ) . This result is consistent with the priority rules that apply to a depositary's security interest in a deposit account and a securities intermediary's rights against its customer. See revised sections 9- 327 and 9-328 . Note that "bank" is broadly defined at section 9-102(a)(8) to include any institution engaged in the business of banking, including savings banks, savings and loan associations, credit unions and trust companies. Section 9-340 changes the prior rule in Oklahoma and many other states that a bank's right of setoff against a deposit account could be subordinate to a prior perfected security interest tracing proceeds into such deposit account. See generally Alvin C. Harrell, Security Interests in Deposit Accounts: A Unique Relationship Between the UCC and Other Law, 23 U.C.C. L.J. 158 (1990).