Together had about 176,000 domestic customers and one non-domestic customer. The firm ceased trading last week, citing the surging price of wholesale gas as the reason.

Ofgem said it had run a ‘competitive process’ to get the best deal possible for Together Energy’s customers.

Funds that current and former domestic Together 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 with their new supplier.

For existing Together Energy customers, energy supplies will continue as normal after they were switched over to British Gas on 23 January.

Customers of Together Energy will be contacted over the coming days about the changes. If customers wish to switch supplier, they can shop around but are advised to wait until the transfer has been completed. Customers will not be charged exit fees if they decide to switch to another supplier.

Neil Lawrence, Ofgem’s director of retail, said: “I am pleased to announce we have appointed British Gas for the customers of Together Energy. We understand that this news may be unsettling for customers, however they do not need to worry. Their energy supply will continue as normal, and customer credit balances will be honoured.

“British Gas will be in contact with customers over the coming days with further information. Once the transfer has been completed, customers can shop around for a better deal if they wish to.”

Since the rise in wholesale energy prices began in August 2021, at least 27 suppliers have collapsed with more being added to the casualty list almost every week.

This has impacted 4 million households and left consumers with a bill of £2.6bn, according to Citizens Advice. The charity says the regulator Ofgem failed to act against unfit energy suppliers.