UKPIA members subscribe to the following principle as part of their relationships with independent retailers.
"Contractual arrangements with independent retailers will refer to, where appropriate, temperature, density, standard and measured litres and mass appertaining to the normal supply point for the service station(s) concerned. The form of reference will be a matter for the individual UKPIA member to decide from time to time, but where appropriate will be clearly and transparently explained to the independent retailer as part of the contractual negotiations."