The trade association said this was a 47 per cent increase compared with May last year.
Figures for May show a net gain to small and mid-tier suppliers of 98,866 which is 27 per cent of all switches. This is down from the previous month, when small and mid-tier suppliers had a 33 per cent net gain.
Of all switches, 39 per cent were between larger suppliers; 39 per cent were from larger to small and mid-tier suppliers; 12 per cent were from small and mid-tier to larger suppliers; and 10 per cent were between small and mid-tier suppliers.
Energy UK has announced the launch of the Energy Switch Guarantee – a set of 10 commitments developed by energy suppliers with the aim of making it clear how customers can switch from one energy supplier to another in a “simple, reliable and hassle-free way”.
Energy UK chief executive Lawrence Slade said: “It’s fantastic news to see that nearly two million people have switched supplier since the beginning of the year. The new Energy Switch Guarantee will give customers the extra boost of confidence to engage in the market.
“Industry has been working hard to put customers at the heart of what we do, and with the CMA set to give its final recommendations, the Guarantee is certainly a step in the right direction.
“The aim is to reach out to those customers who have never switched before, so hopefully we’ll get millions more households engaging in the market.”
MoneySuperMarket energy expert Stephen Murray said: “The Energy Switch Guarantee is a welcome step forward for the industry and will help support customers in taking the step to switch and save money on their energy bills.
“Half of energy customers have never switched providers1 and this initiative will hopefully encourage more switching and improve customer confidence in the process. The Guarantee should also further simplify the process of switching, and promises to ensure the process will take no more than 21 days. However, this length of time could be improved on.
“Recent data from MoneySuperMarket2 shows that 51 per cent of customers could save up to £332 by shopping around for a cheaper deal. It’s free to do and only takes five minutes.”