Thousands have switched away from the big six energy companies due to recent price rises.
The BBC has reported that domestic customers are moving to smaller suppliers in large numbers.
It estimates that 150,000 households have switched to smaller energy companies in recent weeks, even though smaller companies still only account for 3% of the market.
Though many energy companies refused to say how many customers they had lost or gained, many did. First Utility said it gained 100,000 customers and Utility Warehouse said it gained 35,000.
EDF Energy was the only of the big six to reveal any information, saying it had gained 350,000 new customers. This is likely due to it raising its prices by less than half of its competitors.
British Gas, Npower, SSE, EON and Scottish Power all declined to disclose any information.