More than 660,000 customers switched their electricity supplier in February – the highest number yet – according to industry figures.
Energy UK said the figure represented a 60% rise on February 2017, and that over a million customers had switched so far this year.
It said one reason may have been the cold weather during the month.
The most recent figures from regulator Ofgem show high numbers of households also switching their gas supplier.
Last year, 4.1 million domestic customers chose a new gas provider, the highest since 2008.
Gas bills are usually higher than electricity bills, so there is a greater incentive to change supplier.
Energy UK includes business customers in its figures, but Ofgem does not.
Energy UK said another reason for the record number of switchers may have been the publicity campaigns by suppliers and switching websites.
Ofgem has said that consumers can save up to £300 by switching both their gas and electricity provider. The biggest savings are achieved by people moving from the expensive standard variable tariffs to cheaper fixed-term deals.
A fifth of the switches in February were away from the so-called Big Six energy firms to smaller or mid-sized suppliers.
“The energy market has never been so competitive, and it’s great to see record numbers of consumers engaging in the market to get a better deal,” said Lawrence Slade, the chief executive of Energy UK.
The government has published legislation to cap standard variable tariffs before next winter.