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21 October 2021


Eon is one of the UK’s largest energy companies. Find out whether Eon is the best gas and electricity supplier for you, as revealed by its customers.
Sarah Ingrams
Eon big six 480404

Eon is owned by German company Eon SE. It's one of the UK’s largest electricity generators and owns power stations, wind farms and biomass plants.

It's also one of the largest energy suppliers in Great Britain, providing energy to around 3.8 million homes and businesses, although it lost 500,000 customers in 2019. Its customer numbers may be set to increase again though as Eon now owns the majority of Innogy, Npower's parent company.

Eon says it aims to lead the global shift towards new technology and be more sustainable. It sells solar panels and home batteries, and it is installing electric vehicle charging points across the country.

See whether Eon will save you money on energy – use Which? Switch to compare gas and electricity prices.

Eon customer score

Eon came joint-22nd out of the 25 energy companies rated by 7,460 members of the public in the annual Which? customer survey. It ranks jointly with SSE this year, behind British Gas and EDF Energy but ahead of Scottish Power and Npower.

It’s still far behind fast-growing rival Ovo Energy, showing there’s plenty of room for improvement.

It is fair - not cheap and not expensive.

Eon customer

[Eon] was fairly spot on when I rang up but I had to ring up a couple of times to get the issues resolved.

Eon customer

Eon score breakdown

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

Scroll down to find out how long it took to answer the phone to its customers in our snapshot investigation, if live chat is faster and our full verdict on Eon.

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

Which? verdict on Eon

Eon scored a good four stars out of five for bill accuracy and a respectable three stars out of five in three other categories in our survey. That’s not bad, but customers of the highest-scoring brands achieved four stars or more. 

Eon is jointly ranked with SSE, which scored the same for bill clarity, customer service and complaints handling but worse for bill accuracy, where it was rated three stars. Eon was also rated slightly higher for value for money – its customers gave it two stars versus SSE's one.

Data from energy regulator Ofgem reveals that while Eon had a slightly above average number of complaints per 1,000 customers in the first half of 2020 compared with other firms, it solved the majority of those complaints within eight weeks.

Its tariff range includes an online-only tariff with 25% off boiler cover and one exclusively for electric and hybrid vehicle owners, which gives customers a £30 reward equivalent to 850 miles of electricity after you've had the tariff for six months.

Sometimes I've had to wait a while to get through on the phone.

Eon customer

My bill is generally quite accurate even when [Eon] sends an estimated bill.

Eon customer

We found that Eon took 19 minutes 40 seconds, on average, to answer the phone to its customers in our snapshot investigation into energy call waiting times.

This makes it the sixth slowest out of 31 firms we called. The median average wait time was just under six minutes.

Eon offers live chat on its website, and our investigation found it was much faster to get a response in this way, averaging 6 minutes 48 seconds. But live chat wasn't available three of the 12 times we tried, and 12 other firms offering live chat were quicker; the fastest, Outfox the Market, averaged just 10 seconds to respond.

Pros: Offers competitive fixed tariffs sometimes; rewards electric vehicle drivers

Cons: Slow to answer the phone to its customers; live chat sometimes wasn’t available in our investigation

Can I join Eon with a prepayment meter?

Yes, you can join Eon with a prepayment meter and it's installing smart prepayment meters

Smart pay-as-you-go meters mean you can top-up without going to the shop.

Eon's standard prepayment meters can be topped-up at your nearest Post Office, PayPoint or Payzone outlets.

You can get £5 of emergency credit if you can't get to a shop to top-up. You can activate this from your meter and will pay back what you use the next time you top-up.

Does Eon sell renewable energy?

Eon generates a small amount of the renewable electricity used by its customers and buys around a third directly from renewable generators. It also buys renewable energy certificates to match more of its customers’ use with renewable power.

Proportion of renewable electricity sold to domestic   customers
Generates renewable electricity?
Buys renewable electricity directly from generators?
Proportion of customers’ renewable electricity matched by REGO certificates?
Generates or buys directly from fossil fuels?
Sells green gas?
Yes (3%)
Yes (33%)
33% and 20% backed by GoOs

Proportion of renewable electricity according to Eon’s 2020/21 fuel mix. Other responses based on information provided by suppliers in August and September 2021.

Some 81.9% of Eon’s electricity fuel mix is renewable, 1.8% is nuclear and the remainder comes from fossil fuels. 

The renewable electricity it generates is from biomass, which it says is fuelled by responsibly sourced waste and recycled wood. Eon’s Sheffield site uses locally sourced waste wood which otherwise would have gone to landfill. 

Eon also buys around a third of the electricity used by its customers from renewable generators. It says it helped generate many of its supply sites over the last decade. 

This doesn’t match every customer’s use though – a fifth of its electricity is matched with renewable power generated outside the UK, in Europe, using Guarantees of Origin (GoOs).

Find out more about the differences between energy companies’ renewable electricity.

Eon in the news

Eon in 2021

April: Eon will pay out £650,000 after taking 1.6m customers' direct debits early last Christmas, energy regulator Ofgem announced.

So far Eon has paid £55,039 in goodwill payments to customers who told it they had paid extra bank charges, expenses that left them out of pocket or other financial problems as a result of Eon taking their payments early.

You can still claim compensation from Eon if your direct debit was taken early and you suffered financially as a result. Most of the affected direct debits were meant to be taken in January 2021 but were taken on 24 December 2020 instead.

Eon says the payments were taken early due to a technical fault. This followed Eon changing friendly credit hours for prepayment customers between Christmas and New Year.

'Eon failed to conduct the appropriate checks to ensure that this did not lead to any unintended consequences for customers', Ofgem said.

Eon will also pay over £600,000 into Ofgem's fund to help energy customers in vulnerable situations.

March: Around 28,000 Eon customers are being paid a total of £238,000 after they were overcharged when they switched supplier or tariff between 2013 and 2020. It was one of 18 energy firms found by regulator Ofgem to have failed to uphold these rules. Over 1 million customers were affected.

Eon's affected customers will receive £8.49 each, on average.

Eon in 2020

December: Eon took around 1.5m customers' direct debits up to two weeks early meaning some paid for energy twice in one month. Eon explained that an IT issue caused the problems and it would process refunds automatically.

March: Eon's results revealed it lost 500,000 customers in 2019 as more households switched away from the traditional big firms.

Eon in 2019

September: Eon got the go-ahead from the European Commission to take over Innogy, Npower’s parent company. 

July: Eon announced that all of its 3.3 million domestic customers would be provided with 100% renewable electricity at no extra cost. 

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