Okla. Admin. Code § 765:20-3-1
A wholesale used motor vehicle dealer shall not assign a certificate of title to anyone other than a licensed used motor vehicle dealer. A used motor vehicle dealer shall not act as the agent for a wholesale used motor vehicle dealer and an unlicensed person. In every transaction between a wholesale used motor vehicle dealer and a used motor vehicle dealer, there must be evidence of a bona fide sale between the wholesale dealer and the used motor vehicle dealer, such as a bill of sale, check, draft, or other proof of payment, odometer statement, and any other required documents. Any wholesale or used motor vehicle dealer violating the provisions of this paragraph shall be subject to suspension or revocation of license.
Okla. Admin. Code § 765:20-3-1