npower has been ordered to give free energy to customers whose complaints it did not resolve on time.
The energy regulator, Ofgem, said households which had an ombudsman ruling outstanding for more than 28 days against the company would get free power and may also have their debts written off.
The customers have been backed in their complaints by the Energy Ombudsman, but have been forced to wait for their problem to be sorted.
The company admitted to problems with the bills for 700,000 households caused by changing customer data to a new computer billing system.
npower has been the most complained about company in the household energy market for the last two years. Ofgem has threatened them with fines of up to £300 million – 10% of their sales –if they didn’t improve their performance.
An Ofgem investigation into how the Big Six energy companies – npower, British Gas, SSE, E.On, Scottish Power and EDF – conduct their businesses has been running for a year.
npower insists there has been significant progress in tackling the billing backlog and other complaints with only 1,000 billing problems still unresolved.
A spokesman said: “For these 1,000 customers, npower will write off any debt on their account and also provide free energy until the ombudsman’s rulings have been applied in full.
“If there are any customers similarly affected after today we will review on a case by case basis approach in line with the ombudsman’s current policy and also provide free energy where the remedy has not been completed due to our process or system.
“npower continues to make steps to improve its service, including halving overall complaints and reducing ombudsman complaints by nearly 10% since the beginning of this year. Sometimes a delay in finally resolving a complaint can occur, for which we apologise.”
Ofgem senior partner, Anthony Pygram, said: “we are pleased we have been able to secure free energy for npower customers waiting more than 28 days waiting longer than 28 days for a resolution to their ombudsman complaint.
“We welcome the company’s commitment to working with us to put things right. We expect then to implement the ombudsman’s decisions on time. Our intervention has only been necessary because of npower’s failure to do this.”