Okla. Stat. tit. 14A, § 14A-2-204

(1) With respect to any consumer credit sale, refinancing or

consolidation, the parties before or after default may agree in

writing to a deferral of all or part of one or more unpaid

installments.

(2) With respect to a consumer credit sale, refinancing, or

consolidation, which is not precomputed, at the time of deferral the

buyer may agree in writing to a deferral charge that the seller may

make and collect.

(3) With respect to a precomputed consumer credit sale,

refinancing, or consolidation, the seller may make and collect a

charge not exceeding the rate previously stated to the buyer

pursuant to the provisions on disclosure (Part 3) applied to the

amount or amounts deferred for the period of deferral calculated

without regard to differences in lengths of months, but

proportionally for a part of a month, counting each day as one-

thirtieth (1/30) of a month.

(4) A deferral charge may be collected at the time it is

assessed or at any time thereafter.

(5) The seller may, in addition to the deferral charge, make

appropriate additional charges (Section 2-202). The amount of these

additional charges which is not paid in cash may be added to the

amount financed. With respect to a precomputed consumer credit

sale, refinancing, or consolidation, these additional charges not

paid in cash may be considered part of the amount deferred for the

purpose of calculating the deferral charge.

(6) The parties may agree in writing at the time of a

precomputed consumer credit sale, refinancing, or consolidation that

if an installment is not paid within ten (10) days after its due

date, the seller may unilaterally grant a deferral and make charges

as provided in subsection (3) of this section.

(7) No deferral charge may be made for a period after the date

that the seller elects to accelerate the maturity of the agreement,

except in circumstances where the seller waives the acceleration and

the parties then mutually agree to a deferral.

(8) With respect to a precomputed consumer credit sale,

refinancing, or consolidation, a delinquency charge made by the

seller on an installment may not be retained if a deferral charge is

made pursuant to this section with respect to the period of

delinquency.