Green Star Energy has been chosen to take on the customers of Future Energy which stopped trading last week.
It is offering the previous firm’s 10,000 customers the same price as they were paying before.
Green Star Energy said it will also honour all outstanding credit balances, including money owed to both current and former customers.
Ofgem said Future Energy customers will be contacted by Green Star Energy by 6th February, with more information about their tariff and account balance.
Rob Salter-Church, Ofgem’s Interim Senior Partner for Consumers and Competition said: “Our advice for customers of Future Energy is to wait until Green Star Energy contacts you. They will give you more information about the tariff you are on and about your credit balance. Then you can shop around for a better deal if you wish to.”
No exit fees will be charged if customers wish to switch.