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Energy company reviews


By Sarah Ingrams

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Eon is one of the UK’s largest energy companies, supplying energy to around five million homes and businesses. Find out if you should switch to Eon.

Eon, known as Powergen until 2007, is a wholly owned subsidiary of German company Eon SE. It’s the UK’s second-largest electricity generator and owns power stations, wind farms and biomass plants.

See if Eon will save you money on energy – use Which? Switch to find the cheapest gas and electricity.

Eon customer score

Eon came 14th out of the 23 energy companies rated by 8,917 members of the public in the annual Which? customer survey – the biggest of its kind. It’s the highest-ranked of the Big Six energy firms this year, although it has room for improvement in comparison with the top-scoring smaller suppliers.

‘Service with EON is fine. It offers a good service that meets expectations’

Eon customer

The table below shows the breakdown of its score from our latest survey. 

Scroll down to find out what helped Eon inch ahead of its Big Six rivals, including British Gas and Npower, plus how long it took to answer the phone to its customers in our snapshot investigation.

Eon survey results
Area of performance Star rating
Customer service and complaints handling
Value for money
Bills (accuracy and clarity)
Helping you to save energy
Customer score 57%

(Survey: October 2016, responses of 1,111 Eon customers.)

Find out how Eon compares with other energy companies – click to reveal the full results of the best and worst energy companies.

Which? verdict on Eon

Eon scores three stars across the board in our survey, as it did last year. Its overall customer score is slightly higher than other Big Six energy suppliers. Compared with them, more of Eon’s customers say it’s excellent at helping them save energy.

‘Eon’s website contains helpful advice and tips. It also shows how your energy consumption compares with similar properties’

Eon customer

Eon has a loyalty reward point scheme, where points can be exchanged for Tesco Clubcard points or put towards high street vouchers. This is being withdrawn in March 2017.

Eon sometimes offers competitive dual-fuel tariffs, although customer opinions were mixed about its value for money. Some commented on it seeming more expensive, with one customer saying: ‘I think it is no cheaper than any other provider overall, and you have to ensure that you are on the best tariff yourself.' 

Customer service

One Eon customer told us: ‘On the occasions I have telephoned, it has been able to sort out my query – even though it may not be instant.’ Others customers praised Eon’s customer service centre staff, saying: ‘They are always polite and extremely efficient.’

But another said: ‘For simple complaints involving one department only, Eon manages reasonably well. But when something more complex is involved, it would appear that the right hand does not know what the left hand is doing.’ This might explain why other companies score higher for customer service.

We found Eon was the slowest energy company, on average, to answer the phone to its customers in our snapshot energy call waiting investigation. It took 14m18s on average for us to get through to a human – the fastest company average, from small supplier Bulb, was just 27 seconds.

Eon offers live chat on its website and our investigation also found it was much faster to get a response from a human in this way; in just 50 seconds on average.


Our assessment of the accuracy and clarify of Eon’s bills found it scored slightly above average, including making it clear whether the bill is based on an estimated or actual reading, and breaking down the calculations. But there’s still room for improvement, such as making changes to customers’ direct debits clearer and making tariff information labels easier to find out its website.

One customer told us: ‘The wording of the bill is not as straightforward as it could be. It is sometimes difficult to find the details online, ie an itemised bill.’

Pros: Offers loyalty rewards (until 31 March 2017)

Cons: Bills could be clearer and more accurate, slowest to answer the phone to its customers

Eon fuel mix

Where Eon gets its fuel from:

  • 40% renewable
  • 27% gas
  • 16% coal 
  • 11% nuclear 
  • 6% other.

(Note: This information was correct January 2017.)

Eon energy prices

The graph below shows how Eon’s variable (also known as standard) tariff and its cheapest fixed tariff compared with the cheapest fixed tariff on the market over a two-year period. 

As you can see, if you were an Eon customer you could have saved a lot of money if you’d switched to a cheaper energy deal with a different supplier, though it has offered some deals much cheaper than its standard tariff too. 

Eon customers on its standard variable tariff buying both gas and electricity will see their bills increase by £97 on average over the next year after Eon increased its prices 8.8% on 26 April. It raised gas prices by 3.8% and electricity prices by 13.8%, on average, affecting around 2.5million customers.

Eon blamed the rising costs of social and environmental schemes for its price rise and said it would contact vulnerable customers about its cheapest tariff and run a campaign to help customers save money.

The price rise followed Eon’s promise, in December 2016, that it wouldn’t increase its standard energy prices until at least April 2017. It said that it had ‘been working hard behind the scenes to make sure we could make a commitment to our customers […] not to increase our residential standard energy prices until at least after winter’.

See how much money you can save on your energy bill. Use Which? Switch to find the cheapest gas and electricity.

Eon in the news


October: Eon launched a tariff for electric and hybrid vehicle owners which is backed by 100% renewable electricity and green gas. Called the Eon Fixed One Year Electric Vehicle tariff, it's a two-rate deal with a night rate which Eon claims is 33% cheaper than the day rate.

September: Eon announced it will replace its standard variable tariff for customers who have a smart meter fitted with a cheaper fixed-term tariff from early 2018. Customers with a smart meter will be put onto a one-year fixed tariff with no exit fee and will ‘roll over’ onto the latest fixed deal when their tariff ends. Eon said it’s ‘working on options for classic meter customers’ too.

March: Eon withdrew its Reward Points scheme on 31 March. It said customers would still be able to redeem existing points.

February: Eon came joint 80th in a Which? survey of 100 of the biggest brands rated for customer service. Its customer service score was 72%.


September: Energy regulator Ofgem ordered Eon to pay £3.1m for missing appointments with customers and failing to compensate them. Eon has already paid out £1.2m to affected customers but will donate another £1.9m to charity.

February: Energy Secretary Amber Rudd asked regulator Ofgem to investigate after it was revealed Eon’s Age UK Fixed 2 Year paperless tariff, aimed at over 60s, was £938 a year for a medium user, yet its cheapest tariff was only £769. Age UK was also criticised for promoting the more expensive tariff to older customers. Five days later, Eon and Age UK announced they were going to temporarily stop offering the tariff to new and renewing customers. On 19 April, Ofgem announced it had decided there is ‘no case to open an investigation’. It also said it had written to all suppliers to remind them ‘that relationships with charities and other trusted organisations require appropriate oversight’.


November: Energy regulator Ofgem ordered Eon to pay £7m for failing to supply advanced meters to business customers by its April 2014 deadline.

In the second quarter of 2015, Eon had 31.44 complaints for every 1,000 customers, with 78% resolved on the same day or next working day. 

April: Eon was fined £7.75m by the regulator for errors that meant that customers who took the chance to switch suppliers after their bills rose were wrongly charged. This fine came as Eon was charged previously for the same mistake and committed to rectify it.