Okla. Stat. tit. 68 § 717
All persons manufacturing, refining, producing, importing or causing to be imported into Oklahoma, any special fuel and all persons purchasing, receiving or in any manner coming into possession of such fuel, as defined herein, for sale or use must keep a record of all such fuel purchased, received, sold, delivered, used, or otherwise disposed of, including the date and number of gallons of each such transaction, together with the purchase or sales invoices, or copies thereof. All such records and invoices must be kept for a period of at least three (3) years.
All persons making sales or deliveries to any service station or to any person acting as a special fuel dealer or operating as a special fuel user must on or before the twentieth day of each calendar month, file with the Tax Commission a report covering the preceding calendar month, on a form prescribed and furnished by the Tax Commission, scheduling and giving full details of each such sale and such other information as the Tax Commission may require. Provided, however, that if it should be determined by the Tax Commission that a report filed on the basis of the total gallons of special fuel sold or delivered to each station, dealer or user per month is sufficient the Commission is authorized to approve and accept such a report.
Okla. Stat. tit. 68, § 717