Green Network Energy supplied gas and electricity to around 360,000 domestic customers while Simplicity Energy supplied around 50,000 customers.

Under energy regulator Ofgem’s safety net, gas and electricity supply will continue uninterrupted. Any outstanding credit balances will also be protected.

Ofgem will now choose a new supplier to take on all of the two energy firms’ customers. Once a new supplier has been appointed, it will contact customers with further details.

For now though, Ofgem advises the 400,000+ customers not to switch to another energy supplier until a new one has been appointed and it has made contact in the following weeks.

Customers should also take a meter reading as soon as possible to make the transfer process and pay back of outstanding credit balances easier.

The news comes after small energy supplier Yorkshire Energy ceased trading in December, following on from Effortless Energy and Tonik Energy which went bust earlier in 2020.

Philippa Pickford, director of retail at Ofgem, said: “Green Network Energy and Simplicity Energy customers do not need to worry, as under our safety net we’ll make sure your energy supplies are secure and domestic customers’ credit balances are protected.

“Ofgem will now choose a new supplier for you and whilst 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 new tariff.”

Peter Earl, head of energy at comparethemarket.com, said: “The energy market is not immune to the tough environment many businesses are facing as the pandemic continues to take its toll on the economy. Unfortunately, Green Network Energy, Simplicity Energy and their 410,000 combined customers are the latest to be impacted.

“However, customers should be reassured that their supply of energy and credit balance will be protected, since energy is an essential utility. They do have options though and once they have made contact with their new supplier, they can look around the market to find a supplier, service and price that works for them.”