Okla. Stat. tit. 68 § 714
The liability for the tax imposed by this act shall arise and accrue on the first use of special fuels in this state either against the special fuel dealer at the time of delivery of special fuel into the supply tank or tanks of a motor vehicle or against a special fuel user operating a motor vehicle upon the highways of this state, the operation of which is subject to and liable for the payment of said tax. The liability for said tax shall accrue against a special fuel user importing special fuel into this state in the supply tank or tanks of a motor vehicle using Oklahoma highways for commercial purposes at the time and place such motor vehicle shall enter upon a public highway of this state.
Any special fuel dealer or special fuel user who as lessee, in furtherance of his business enters into a lease for one or more trips or a contract or other arrangement, with another person for the operation of a motor vehicle, the operation of which vehicle is or will be subject to the tax herein imposed, shall be deemed to be the operator of said vehicle or vehicles, and shall report and pay the tax accruing by reason of such use under said lease, or contract. Provided that this provision shall not be construed as relieving any lessor or person acting as a special fuel user from the payment of the tax herein imposed in cases where the lessee, with whom such lessor has entered into a lease or contract has not obtained a special fuel dealer's or user's license under this act. Provided further, nothing herein shall be construed as requiring the filing of more than one report covering a given special fuel use operation or as requiring the payment of the tax herein imposed more than once on the same special fuel.
Okla. Stat. tit. 68, § 714