2005 California Business and Professions Code Sections 13520 Article 11. Basis of Settlement

13520.  It is unlawful for any distributor or for any broker to sell
any product to a retailer or to any person, when the quantity
distributed in any single delivery to a single location is 5,000 or
more gallons, as, or purporting to be, gasoline or diesel fuel,
unless the distributor or broker, as the case may be, offers to
invoice the purchaser for such gasoline or diesel fuel on the basis
of temperature-corrected gallonage to 60 degrees Fahrenheit for all
such deliveries to the purchaser over a period of 12 consecutive
months and settles his accounts with the purchaser on the same basis.