However, these results were from one-tenth the number of subscribers compared with their major competitors.
The sample size for pay-as-you-go phones was 2,587 subscribers, made up of Asda (50), Tesco (275), Virgin (312), O2 (531), Vodafone (455), Orange (651), T-Mobile (229), and Fresh (31).
Which? measured customer satisfaction by cost of using the phone, network coverage, customer service, range of handsets, cost of use abroad and accuracy of bills. The average score for contract suppliers was 56%; the pay-as-you-go average was 55%.