Green Network Energy and Simplicity Energy have announced they are ceasing to trade.
The two energy suppliers are the latest to be added to the list of businesses that went bust during the coronavirus pandemic.
Green Network Energy has around 360,000 domestic customers as well as a smaller number of non-domestic customers, while Simplicity Energy is serving around 50,000 domestic customers.
Ofgem said it will appoint a new supplier for the companies’ customers.
The government regulator has advised customers not to switch to another energy supplier until a new one has been appointed and to prepare a meter reading for when the new supplier contacts them.
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.”