Many British energy companies, often supplying both gas and electricity to homes and businesses, have struggled in the face of soaring wholesale energy costs, because the regulator's price caps limit how much of the increases can be passed on to customers. The latest quartet to cease trading, comprising Omni Energy, MA Energy, Zebra Power and Ampoweruk, has a combined total of about 23,700 domestic and non-domestic customers, who will be found new suppliers, Ofgem said.
Ofgem said in a statement: "In recent weeks there has been an unprecedented increase in global gas prices which is putting financial pressure on suppliers.
“Ofgem is working closely with government and industry to make sure customers continue to be protected this winter.”
A total of roughly two million customers have been forced to change energy companies.
Additionally, Bulb Energy, Britain's seventh-biggest domestic energy supplier with 1.7 million customers, is widely believed to be on the brink of collapse.
Prime Minister Boris Johnson and Business Secretary Kwasi Kwarteng are understood to be working on a contingency plan if the worst happens.
Customers' potential new energy costs will be covered by the regulators price cap, but if they were on cheaper fixed tariffs they may have to pay more with their new supplier.
The cap is updated twice a year and rose by between 12 and 13 percent from the start of October.
However, wholesale prices have risen far more since that cap was set in August.
Ofgem said last week will examine whether the cap reflects the costs and risks facing energy suppliers and said a decision on any changes would be published in February, when the next price cap level will be announced.
JUST IN: Hit back, Boris: UK must teach Macron a lesson, says Ann Widdecombe
"Ofgem will choose a new supplier for you and while we are doing this our advice is to wait until we appoint a new supplier and do not switch in the meantime.
"You can rely on your energy supply as normal. We will update you when we have chosen a new supplier, who will then get in touch about your tariff."
Speaking to Express.co.uk in October, Alan Brown, the SNP’s MP for Kilmarnock and Loudoun, urged the Government to step in to shield the least wealthy from the impact of soaring prices, warning costs would undoubtedly be passed on to consumers.
Mr Brown, chairman of the APPG on Energy Costs, said: The risks though are ever-increasing costs and pressure on Ofgem to continue raising the cap.
“Also, every time a company goes under, any additional costs are picked up by all energy users through levies on our bills.
“Customer credit is protected when a company goes under which is good.
“However, it is again other energy users that have to cover the cost of the credit transfer to the new energy company.”
Mr Brown said the UK Government needed to do more to help with what he called “the cost of living crisis”.
He added: “Let’s not forget as prices have increased so has the VAT payments to the Treasury.
“They are making more money from oil and gas revenues than forecast and more money off petrol duties.
“They should re-circulate this unexpected windfall to help those in need.”
Commenting on the latest developments, Gillian Cooper, Head of Energy Policy for Citizens Advice, said: “Suppliers continue to fall like dominoes. It’s customers who are paying the price, with uncertainty, inconvenience and ultimately higher bills.
“Last week, Ofgem set out how it intends to ‘raise the bar’ for supplier standards and improve their resilience in the short-term. This is a positive step, but it's clear that existing rules and their enforcement, has not been enough.
“Longer-term, Ofgem will need to do more to make sure companies are financially sound and provide good customer service. This should include protecting people from the loyalty penalty, which prior to the cap allowed companies to profit from those who didn’t or couldn’t switch.”