More than 1 million customers changed their energy tariffs in November and December last year, according to the latest figures.
Electralink recorded the data, which shows that 1,006,435 consumers changed their tariffs at the end of 2013.
23% moved over to the smaller suppliers, with a gain of 229,863 customers from the major suppliers.
The figures show there was a peak at the end of the year with just under a third of the 3.5 million switches being made in November and December. This was after the larger suppliers announced their price increases.
Angela Knight, chief executive of Energy UK said: “Increased switching is a welcome sign that the energy industry is becoming more competitive, clearer and working for its consumers.
“There has been a sharp increase in the number of customers switching and those shopping around for a deal which suits their individual circumstances.
“And competition is alive and well with people choosing new entrants to the market and smaller suppliers rather than just sticking with established companies.”