We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies as per our policy which also explains how to change your preferences.

Big Six reviews


By Sarah Ingrams

Article 4 of 6

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.


Npower is one of the UK's Big Six energy companies. But is Npower cheap and is its customer service any good? We reveal all.

Npower is part of the Innogy group, a Europe-wide energy company based in Germany. It operates coal, oil, biomass and gas-fired power stations.

It's currently merging with SSE to create a big new energy retail and services company. The Competition and Markets Authority gave the merger the provisional go-ahead in August and the new company intends to be formed by late 2018 or early 2019. In the meantime, Npower says it’s ‘business as usual’.

Read on to find out what Npower’s customers think of it and see if Npower offers value for money.

See how Npower compares on price with your current deal – compare energy prices with Which? Switch.

Npower customer score

Npower came last in our energy companies satisfaction survey again this year. This is nothing new, as Npower brings up the rear in our table every year. 

This year, it was 31st out of the 31 energy companies included, rated by 8,761 members of the general public.

Npower score breakdown

See below for the breakdown of Npower’s score from our latest survey.

Then scroll down to find out more about Npower’s prices, where it gets its fuel from and why it wants to merge with rival SSE.

Find out how Npower compares with other energy companies – we reveal the full results of the best and worst energy companies.

Which? verdict on Npower

Once again, Npower has the lowest customer satisfaction score of all the energy companies included in our survey. But this year, other firms (Spark Energy and Extra Energy) score closer to it.

Npower has the joint-highest (with Spark) percentage of very dissatisfied customers (5%).

‘Npower takes a long time to deal with queries. And even then, the problem isn't solved.’

Npower customer

Customers also rate Npower as terrible value for money overall; it was one of just two firms to score two stars for this in our survey. The other was British Gas.

Npower’s standard variable tariff is the priciest of the Big Six energy companies, and often £300 pricier per year on average than the cheapest deal on the market. But it does sometimes offer cheap deals.

‘They tie you in with cheap rates then rack up the price after a few months.’

Npower customer

Npower customer service

People told us that they join Npower for lower prices but then leave because bills are too high, their fixed deal ends or customer service is poor. 

Npower had the highest percentage (29%) of customers citing poor customer service as a factor in their leaving it. So our analysis of our customer survey results suggests customers are tempted by good prices but driven away in frustration at its service.

‘It is hard to get to speak to a real person and they can never deal with your query.'

Npower customer

But the foundation is there for improvement. Our evaluation of Npower’s procedures and practices*, including on product management and customer service, has found it to be well above average for two years running. Although it still has a lot of work to do to keep its customers satisfied.

‘Easy-to-use app which shows statements, future estimated usage and ease of sending meter readings.’

Npower customer

Our investigation into energy companies’ customer service waiting times found Npower took over 20 minutes on average to put us through to a human when we phoned its customer services. Only two companies took longer.

Plus it's not much faster to use live chat: we found we got a human response in 17min 19sec on average in our September 2018 investigation.

Pros: Offers some cheap deals and our analysis found its policies are better than those of many other suppliers

Cons: Lowest-scoring supplier, customers don’t think it’s good value for money

*(September 2017)

Npower fuel sources

Npower energy prices

The graph above shows how Npower’s variable (also known as standard) tariff, its priciest tariff (if different) and its cheapest tariff compared with the cheapest tariff on the market over a two-year period. 

If you were an Npower customer and on its variable tariff, you could have saved a lot of money over the last year by switching to a cheaper energy deal – including Npower’s own cheapest fixed tariff. In our latest figures, Npower's standard deal is more than £100 pricier than its cheapest fixed deal, for the average user.

Npower has announced a 5.3% price rise for the 1m customers on its standard variable tariff from 17 June 2018. This will add £64 to dual-fuel customers’ bills, on average, over the next year.

The increase makes its standard tariff the most expensive of the Big Six energy suppliers, costing £1,230 per year for the average energy user.

Npower also raised prices in March 2017. It increased electricity prices by 15% and gas prices by 4.8% for customers on its standard tariff, adding £109 per year to the average energy bill.

Npower in the news


September: Npower shared personal details of 5,000 of its customers in letters posted to other customers. You could be affected if you have solar panels on your roof.

Quarterly statements showing the amount of money customers would receive as part of the feed-in tariff scheme also contained other customers’ names, addresses and payment amounts. No bank details were released, Npower said.

Npower says it is ‘urgently investigating’ and has told the Information Commissioner’s Office about the data breach.

Find out your rights if your data has been lost.

August: Npower and SSE’s merger was provisionally cleared by the CMA which said it ‘does not raise competition concerns’.

Innogy, of which Npower is a subsidiary, said that preparations for the new merged energy company are ‘on track’ and it should be listed on the London Stock Exchange in late 2018 or early 2019.

Earlier in the month, Npower was fined £2.4m by Ofgem for failing to install advanced meters for some of its electricity business customers by the 2014 deadline.

May: The proposed merger between Npower and SSE must undergo further investigation to determine whether it gets the go-ahead, the Competition and Markets Authority (CMA) announced. It said that the firms hadn’t provided sufficient evidence to address its concerns that the merger would result in a ‘substantial lessening of competition’ which could see some customers’ bills increase.

March: 155,000 customers left Npower over the past year. Npower Boss Paul Coffey said the losses ‘can largely be attributed to the first quarter’ of the year. This was after Npower increased its prices.

Npower reported a £56m loss last year and now has around 4.56m customers.


November: Npower and SSE announced plans to merge into a new energy supplier.

Npower’s parent firm, the German company Innogy, would join its business supplying households in the UK with SSE’s to form an energy company of a similar size to British Gas (the biggest of the Big Six firms).

Npower CEO Paul Coffey said: ‘In order to be a really successful energy company, we need scale and skills – and this deal will deliver both’.

September: Npower came joint-94th in a survey of 100 of the best and worst big brands for customer service, with a customer service score of 67%.

Don’t pay too much for energy – use Which? Switch to find the cheapest gas and electricity deal.