Small and medium-sized energy firms have topped the table when it comes to service, leaving the major players trailing in their wakes.
For the second year in a row, Octopus Energy was rated as the best of the bunch after consumer association Which? asked people what they thought of their supplier.
But it wasn't the only smaller company winning big approval from its customers, with Ebico, Bulb Energy, Pure Planet, People’s Energy and Powershop following it at the top.
By contrast, the traditional "big six" all finished in the bottom third of the table, with Scottish Power ranked lowest of them.
Which?'s Natalie Hitchins said: “Consumers have dozens of energy suppliers to choose from - and it is clear that some newer challenger providers are better than their larger counterparts at keeping customers happy and delivering a better service.
“Customers shell out hundreds, sometimes thousands, of pounds a year on their gas and electricity bills so it is right that they expect good service from their energy supplier."
Which? asked more than 8,000 people across the UK what they thought of their energy supplier, getting them to rate companies on things like value for money, customer service, bill accuracy and digital tools.
A third of British Gas customers, three Scottish Power customers in 10 and around a quarter of EDF Energy, Eon, Npower and SSE customers said they had experienced problems in the past year.
By contrast, just one Octopus Energy customer in nine reported a problem.
The highest-scoring big firms were SSE (now part of Ovo) and Eon.
But it was not quite all good news for smaller players, with Robin Hood Energy dropping from second place last year to a mid-table ranking after smaller proportion of its customers said they would recommend the firm.
Together Energy also fell - from mid-table to dead last - scoring just two-star ratings from customers for billing accuracy, clarity, customer service and value for money.
