More than 415,000 consumers switched electricity supplier in February - a 21% increase on the month before, figures show.
The number is the highest for February in the past three years and comes as households face a spate of energy price rises.
There was also an increase in the number of customers switching from larger to small and mid-tier suppliers, with 110,000 or 27% of switches following this path, trade body Energy UK said.
Lawrence Slade, chief executive of Energy UK, said: "These ever-increasing switching numbers, alongside twice the number of existing customers making a tariff change with their existing supplier, demonstrate that competition is working for more and more consumers.
"If customers are unsure if they are on the best deal, check either by speaking to their current supplier or one of the 50 suppliers active in the market."
Npower, EDF and Scottish Power are among those to have ramped up bills, with many blaming rising wholesale costs.
Co-operative Energy announced it would increase the cost of its standard variable tariff by an average of 5%, a change that will affect around 96,000 customers when it comes in from April 1.
E.On is to increase its standard variable dual fuel prices by an average of 8.8% from April 26.
Figures released last month by regulator Ofgem showed switching has surged to a six-year high as householders increasingly shop around for better deals on gas and electricity.
Customers swapped their energy providers 7.7 million times last year, a rise of 1.7 million, almost 30%, on 2015.