CNG Energy has ceased trading amid soaring wholesale energy costs.
The North Yorkshire based firm is the 19th to cease trading since September.
The collapse of the struggling energy firm has left 41,000 business customers in need of rescue from Ofgem.
The market regulator has confirmed customers’ energy supplies will continue as they look to designate them a new supplier.
However, businesses remain unprotected by its £1,277 annual price cap for average use which is only provided to domestic consumers.
This means businesses could bear the brunt of rising wholesale costs and could be exposed to higher prices.
CNG Energy’s customers also won’t be guaranteed funds that have been paid into their account where they are in credit, unlike domestic consumers.
Neil Lawrence, director of Retail at Ofgem, said: “Ofgem’s number one priority is to protect customers. We know this is a worrying time for many people and news of a supplier going out of business can be unsettling.”