Okla. Stat. tit. 15, § 15-677: Commission - Time when due

For purposes of the Sales Representatives Recognition Act, the

time at which a commission is due to a sales representative shall be

determined in the following manner:

1. If the contract between the principal and the sales

representative is in writing and its terms unambiguously and clearly

specify when the commission is due, the terms of the contract shall

control the determination;

2. If the contract between the principal and the sales

representative is not in writing, or if the contract between them is

in writing but its terms do not specify when the commission is due

or its terms are ambiguous or unclear, the past practice used by the

principal and the sales representative shall control the

determination; or

3. If neither paragraph 1 or 2 of this section can be used to

clearly ascertain when a commission is due, the custom and usage

prevalent in this state for the industry of the principal and sales

representative shall control the determination.