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Big Six reviews


By Sarah Ingrams

Article 3 of 6

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Eon is one of the UK’s largest energy companies. Find out if Eon is the best gas and electricity supplier for you, as revealed by its customers.

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.

It supplies energy to around 5m homes and businesses.

Eon recently launched a tariff aimed at owners of electric and hybrid vehicles, and sells solar panels and home batteries.

See if 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 31 energy companies, rated by 8,761 members of the public, in the annual Which? customer survey. It’s joint-highest-ranked of the Big Six energy firms this year, with EDF Energy.

That said, it still has room for improvement in comparison with the top-scoring smaller suppliers.

‘No energy supplier is great, but Eon is as good as anyone else.’

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, what its prices are like and the full Which? verdict on Eon.

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 a consistent three stars across the board in our survey, as it has done for the past two years. That’s not bad, but rival EDF’s customers rate its bills and phone customer service good; Eon's customers consider it ‘fair’ in these areas.

‘Bills are often based on estimates that aren’t especially accurate.’

Eon customer

Its tariff range includes Cap and Track, which reviews prices every quarter depending on wholesale costs, but caps the cost at your initial quote. It also has an online-only tariff, and one backed by 100% renewable electricity.

Eon sometimes offers competitive dual-fuel tariffs, although customer opinions were mixed about its value for money.

‘If I shopped around I could probably find cheaper deals.’

Eon customer

Eon's customer service

We found Eon was among the five slowest energy companies, on average, to answer the phone to its customers in our snapshot investigation into energy call waiting times

It took 17min 29sec on average for us to get through to a human – the fastest company average, from small supplier Affect Energy, was just 10 seconds.

‘They always pass me around to different people on the phone, and nobody seems to know how to sort any problems out’

Eon customer

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 4min 3sec on average. But other firms were far quicker; the fastest took just 10 seconds on average to respond on live chat.

Compared with other Big Six suppliers, it sources the greatest proportion of its electricity from coal (see its full fuel mix, below).

Pros: Offers some competitive fixed tariffs

Cons: Slow to answer the phone to its customers

Eon fuel sources

Eon energy prices

The graph above shows how Eon’s variable (also known as standard) tariff, its priciest tariff (where different to its standard tariff) and its cheapest tariff compared with the cheapest tariff on the market over the last two years.

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, although it has offered many deals much cheaper than its standard tariff too.

Eon customers on its standard tariff saw their bills increase from 19 April 2018, after the energy firm scrapped dual-fuel and paperless billing discounts worth £30 per year. 

Plus customers who pay by cash or cheque saw their standing charge rise by around £20 each year.

Although this isn’t a direct price increase, customers can see up to a 2.67% increase on their bills over the next year.

Eon also increased its gas and electricity prices by 8.8% in April 2017. Around 2.5 million customers saw bills increase by £97 over the following year.

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


June: Eon announced it will raise prices by 4.8% for gas and electricity customers on its standard variable tariff from 16 August.

For some customers, this will be the second time their bills have increased in 2018. The price rise means affected customers will pay £55 more per year on average. Eon said its price increase was due to ‘the significant rise in the cost of wholesale energy’.

March: Two money-saving initiatives were scrapped, Eon announced on the coldest March day on record. From 19 April, Eon customers on its standard variable tariff stopped receiving dual-fuel and paperless billing discounts. Together these were worth £30 per year. 

Eon also increased the standing charge for customers paying by cash or cheque.


November: 200,000 customers switched away from Eon this year, the firm announced. Eon finance chief Marc Spieker said that ‘fierce competition , regulatory changes and adverse exchange rates’ were behind the exodus.

October: Eon launched a tariff for owners of electric and hybrid vehicles, 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 that Eon claims is 33% cheaper than the day rate.

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

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%.