Industry watchdog Ofgem said Omni Energy Limited, MA Energy Limited, Zebra Power Limited, and Ampoweruk have all stopped trading, leaving around 23,700 customers – both domestic and non-domestic – in need of a new supplier, which will be appointed by the regulator.
They join more than a dozen suppliers that have gone bust in the country in recent weeks because of high wholesale energy prices.
Ofgem said in a statement that "there has been an unprecedented increase in global gas prices which is putting financial pressure on suppliers."
It said it is working closely with the government and industry to make sure customers continue to be protected this winter.
Under Ofgem’s safety net, customers’ energy supply will continue and funds that domestic customers have paid into their accounts will be protected, where they are in credit. Domestic customers will also be protected by the energy price cap when being switched to a new supplier.
Ofgem’s advice to affected customers is to wait until a new supplier has been appointed and contact them in the following weeks before they look to switch to another energy supplier.
It also said customers should have their meter reading handy for when their new supplier contacts them as this will make the process of transferring customers over to the chosen supplier easier.
Neil Lawrence, director of retail at Ofgem, said: “Ofgem’s number one priority is to protect customers. We know this is a worrying time for many people and news of a supplier going out of business can be unsettling."
Benchmark natural gas prices in the UK and in Europe have tripled this year due to a combination of factors, including low gas reserves, strong commodity and carbon prices, heightened global demand, and low wind output.