Okla. Stat. tit. 68, § 68-716

Every person acting as a special fuel dealer who sells and

delivers any special fuel, as defined in this act, into the fuel

supply tank or tanks of any motor vehicle in this state must, at the

time of such delivery, make and deliver to the person owning or

operating such vehicle (the purchaser of such fuel or his agent) an

invoice covering each such delivery, showing the name of the

operator or purchaser, the date, the name and address of the special

fuel dealer and his special fuel dealer's license number, the number

of gallons of special fuel delivered, the place of delivery, the

correct name of such fuel, the price per gallon and total sale price

of the amount delivered, and such other information as the

Commission may require. Each such invoice must be made in duplicate,

be identified by consecutive numbers printed thereon, and each

special fuel dealer must furnish said invoices and retain one copy

thereof and be able to account for each numbered delivery invoice

and each copy thereof.

The invoices required by this section must be demanded by every

person purchasing and receiving a delivery of special fuel into the

supply tank of a motor vehicle in Oklahoma at the time of such

delivery and such person shall carry any such invoice with the

vehicle until the fuel covered by same is consumed. If the special

fuel is delivered by a licensed dealer or user into the supply tank

or tanks of his own vehicles, a notation or proper record of same

shall be made on the invoice.

Every person making such sales and deliveries of special fuel

and every person so receiving and purchasing special fuel must each

retain one copy of each such invoice as a part of his permanent

records for a period of at least three (3) years.

Every special fuel dealer or user who shall make any delivery of

special fuel into the supply tank of any motor vehicle owned and

operated by such dealer or user shall make and maintain for at least

three (3) years a record of all such deliveries of special fuel

showing such information as the Commission may require.