Okla. Stat. tit. 12A, § 12A-3-112: Interest

INTEREST

(a) Unless otherwise provided in the instrument, (i) an

instrument is not payable with interest, and (ii) interest on an

interest-bearing instrument is payable from the date of the

instrument.

(b) Interest may be stated in an instrument as a fixed or

variable amount of money or it may be expressed as a fixed or

variable rate or rates. The amount or rate of interest may be

stated or described in the instrument in any manner and may require

reference to information not contained in the instrument. If an

instrument provides for interest, but the amount of interest payable

cannot be ascertained from the description, interest is payable at

the judgment rate in effect at the place of payment of the

instrument and at the time interest first accrues.