Okla. Stat. tit. 54, § 54-1-104
Supplemental Principles of Law
Supplemental Principles of Law. (a) Unless displaced by
particular provisions of this act, the principles of law and equity
supplement this act.
(b) If an obligation to pay interest arises under this act and
the rate is not specified, the rate is that specified in Section 727
of Title 12 of the Oklahoma Statutes.