The energy firm rankings are based on a customer satisfaction survey of more than 9,000 energy customers which asks a series of questions related to their supplier and how satisfied they are with them. UW scored highly for its customer service overall and the quality of its communications about energy costs.

For Which?’s own detailed assessment, UW scored 80% - the highest of all suppliers who were assessed - scoring highly for its smart meter target performance and supporting customers who need it. 

Taken together, the overall result represents a big improvement for UW compared to last year’s rankings, with UW’s overall score increasing by 10% to 75% and UW’s Which? assessment score increasing by 16%. 

Stuart Burnett, Co-CEO of Utility Warehouse, said: “We’re delighted to have secured the highest overall score for Which?’s latest annual energy firm rankings. As many people continue to face cost-of-living pressures, we’re seeing increasing numbers of customers join Utility Warehouse to take advantage of our market leading services, including our fixed rate energy tariffs. It’s thanks to our multiservice business model, which enables customers to bundle services together, that we can deliver big savings for households on their monthly bills.”

More than 62,500 additional households switched to UW in the first 6 months of FY24, representing an annualised growth rate of over 14%. With over 950,000 households taking more than 3 million services from UW, the business is on track to pass the one million customer milestone during the current financial year. 

Read the full rankings from Which? on their website.