Okla. Stat. tit. 68, § 68-606: Accrual of liability - Persons liable - Exemptions

The liability for the tax imposed by this article shall arise

and accrue against the person operating a motor vehicle, the

operation of which is subject to said tax, at the time and place

said motor vehicle shall enter upon the highways of this state.

Provided, however, a lessor who is engaged in the business of

leasing for compensation motor vehicles and equipment he owns

without drivers to carriers or other lessees for interstate

operation may be deemed to be the Motor Fuel/Diesel Importer for Use

when he supplies or pays for the motor fuel or diesel fuel consumed

in such vehicles, and such lessor may be issued Motor Fuel/Diesel

Fuel Importer for Use license. Any lessee may exclude motor

vehicles of which he is lessee from his reports and liabilities, but

only if the motor vehicles in question have been leased from a

lessor holding a valid Motor Fuel/Diesel Fuel Importer for Use

License.