More than 614,000 people swapped supplier in the UK in November, double those who switched in October 2013.
It was also the highest number of people switching since 2010, suggesting the recent furore over rising energy bills and profits is sinking in with consumers.
The figures from data company Electralink also show 125,000 of those switching were changing to a company outside of the ‘Big Six’ energy suppliers.
Even more people may have moved tariff as these figures don’t take into account those that have switched to a more suitable tariff at the same company.
The retail electricity market has been criticised recently as too complicated and opaque for domestic energy users get a good energy deal.
But trade body Energy UK which asked the firm to gather the new figures described them as “proof” the retail energy market is working well.
Angela Knight, Chief Executive of Energy UK said: “The sharp increase in the number of people switching between companies and the number of fast growing smaller suppliers… is an example of the energy market working, putting the needs of the customers first, providing a competitive and transparent market.”