1 In their latest 2017 report, Which? Magazine surveyed almost 8,917 UK energy bill-paying adults in 2016 about their energy suppliers. Suppliers were then ordered according to their customer score, based on overall satisfaction with the supplier (www.which.co.uk/energy/saving-money/reviews-ns/energy-companies-reviewed/best-and-worst-energy-companies/).
2 A single-rate or Economy-7 credit or pay-as-you-go meters