Ofgem has ordered seven energy suppliers to pay a total of £17.9 million in outstanding Renewables Obligation (RO) payments.
The regulator said if the suppliers fail to make the payments, it could take further enforcement action.
That could include suspending companies’ licence.
Earlier this month, Ofgem consulted on issuing final orders for Ampower, Whoop Energy, Goto Energy, Home Energy Trading and Colorado Energy for unpaid RO payments.
Since then, Goto Energy and Colorado Energy ceased to trade while Home Energy Trading has paid its obligation.
Ampower and Whoop Energy have been issued with final orders and can pay until 31st October.
Ofgem also contacted five additional active suppliers which are yet to meet their obligation and were unable to provide satisfactory assurances that they will be able to pay by 31st October.
These suppliers are Delta Gas and Power, Entice Energy, MA Energy, Neon Reef and Together Energy.