Okla. Stat. tit. 15, § 15-215: Amount presumed to be damages, provision for

A. A stipulation or condition in a contract except a contract

to purchase and sell real property, providing for the payment of an

amount which shall be presumed to be the amount of damage sustained

by a breach of such contract, shall be held valid, when, from the

nature of the case, it would be impracticable or extremely difficult

to fix the actual damage.

B. A provision in a real estate sales contract, providing for

the payment of anamount which shall be presumed to be the amount of

damages sustained by a breach of such contract, shall be held valid

and not a penalty, when such amount does not exceed five percent

(5%) of the purchase price. In the event such amount exceeds five

percent (5%) of the purchase price, such provision shall be held

invalid and a penalty unless the party seeking to uphold the

provision establishes that such amount is reasonable. If such

provision is valid under this subsection, the limitations of Section

28 of Title 23 of the Oklahoma Statutes do not apply.