Sainsbury’s Energy Customers Moved to British Gas Hundreds of thousands of Sainsbury’s Energy customers have now been switched to British Gas. It comes after the company announced it would not be taking on any new customers in February and moving existing customers to the Big Six supplier this month. Sainsbury’s Energy was a white label of British Gas, which meant the latter company was also supplying gas and electricity and energy services to consumers under the Sainsbury’s Energy brand. Despite the move, customers’ terms and conditions will remain the same – any debt or credit will be passed over to British Gas. Customers can shop around and look for a better deal on the market if they wish to do so.