When you have an All Star fuel card, you pay a network service fee for each card transaction. This fee covers the cost of maintenance, service, and network improvements. The size of the fee will depend on fuel consumption, but it will not be more than 2% of the fuel bill.
We should point out that Allstar's invoicing records Value Added Tax payments for reclaiming the tax from HM Revenue and Customs.
Be careful: sometimes an introductory rate will lock you into higher-price forecourts and not allow you to fill up at cheaper stations.