Zog Energy ceased trading today, marking another dark chapter for the struggling industry.
The market regulator will appoint a new supplier for its 11,700 gas and electricity customers.
Customer’s supplies are secure, and funds that domestic customers have paid into accounts will be protected if they are in credit.
Wholesale costs have increased five-fold this year, with 24 energy firms collapsing in the past three months.
Four million customers have been directly affected by the developments.
Last week, Bulb became the first de-facto nationalised energy firm since the 2011 Energy Act.
In particular, energy firms have struggled to pass on rising costs to consumers due to the price cap – which limits charges to £1,277 per year for average use.
Suppliers have also failed to hedge effectively ahead of potential market shocks.
Earlier this month, Ofgem pledged to review the price cap.
The group’s CEO told the House of Lords on Tuesday that capital controls and hedging limits could also be introduced.