E.ON Next So Energy (September 2026)
Overview
E.ON Next is the stronger option with a higher Citizens Advice score and a significantly cheaper fixed tariff, though So Energy offers a cheaper variable deal.
E.ON Next emerges as the stronger option, supported by a higher Citizens Advice score and a notably cheaper fixed tariff. Although both suppliers hold a 4.5-star Trustpilot rating and price their cheapest overall deals almost identically, E.ON Next performs better across independent service metrics.
About E.ON Next and So Energy
Who is E.ON Next?
E.ON Next is part of the German energy group E.ON. It was set up in 2020 to take on customers after E.ON bought the npower brand. Today, it is one of the UK's largest domestic energy suppliers. It uses the Kraken platform to run its customer service and billing. As well as energy tariffs, it offers home technology like solar panels, batteries, and electric vehicle chargers.
Who are So Energy?
So Energy started in 2015 as a challenger brand. In 2021, the Irish state-owned company ESB bought a majority stake, and the two companies merged their UK customer bases. It is now a mid-sized supplier. It focuses on simple tariffs and lets customers vote on where it buys its renewable electricity. It also offers home energy products like solar panels, batteries, and boiler cover.
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Tariffs and pricing
Under our assumptions, the cheapest tariffs from E.ON Next and So Energy are separated by just £1 a year. E.ON Next's lowest-priced deal is the Next Fixed 24m Exclusive v11 at £1,510 a year, which requires a 24-month contract and includes a £200 exit fee. Conversely, So Energy's most affordable option is the So Green Tracker 24m variable tariff, which requires a smart meter. Priced at £1,508 a year, it also runs for a 24-month term and carries a £190 exit fee.
For households looking to lock in their rates, E.ON Next provides the more competitive fixed deal. Its lowest fixed option is £225 a year cheaper than So Energy's equivalent, which costs £1,735 a year over an 18-month term with a £190 exit fee. However, So Energy may suit those seeking a variable rate, as its cheapest variable option costs £1,508 a year, compared to £1,560 a year from E.ON Next.
E.ON Next and So Energy: Tariff Options
E.ON Next
E.ON Next offers standard variable and fixed tariffs for everyday household use, with fixed terms lasting 12 or 24 months. It also has specialist options for electric vehicle drivers, heat pump users, and homes with solar panels and battery storage.
So Energy
So Energy keeps its range simple with standard variable and fixed tariffs, offering fixed terms from 12 to 24 months. It also has tracker tariffs and a dedicated option for electric vehicle owners.
Customer reviews
Both suppliers hold a 4.5 out of 5 rating on Trustpilot. This is based on a very high volume of reviews for E.ON Next and a high volume for So Energy. E.ON Next has a slightly higher five-star review share, at 75% compared with 73% for So Energy.
Reviewers frequently commend E.ON Next for helpful staff and a smooth switching process, although some report rising costs and occasional communication gaps. So Energy customers similarly highlight polite representatives and straightforward account management, while noting drawbacks such as long telephone wait times and expensive pricing structures.
Looking at the annual Which? survey, E.ON Next achieves a higher overall score of 66 out of 100, compared to So Energy's 60 out of 100. Furthermore, E.ON Next receives an 8 out of 10 rating for smart meters, placing it ahead of So Energy, which scores 2 out of 10 in this category.
App quality and features
On Google Play, So Energy holds a higher rating of 4.6 out of 5, whereas E.ON Next scores 4.3 out of 5. It is worth noting that So Energy's score is drawn from a very small sample of just 138 ratings, making direct comparisons difficult against E.ON Next's 16,000-plus ratings. Both applications have received recent updates.
So Energy scores 4.7 out of 5 from 225 ratings on the App Store. A recent sample of its iOS reviews indicates a mix of feedback; some users praise the clear layout, while others report issues when submitting meter readings. E.ON Next does not currently have an available iOS app rating.
Service and support
E.ON Next achieves a stronger position in the Citizens Advice rankings, placing 3rd overall with a score of 3.71 out of 5. In contrast, So Energy ranks 12th with a score of 2.86 out of 5. Both suppliers maintain formal vulnerability commitments registered with Citizens Advice.
For telephone support, So Energy connects customers faster. Its average call centre wait time is 1 minute 6 seconds, compared to 2 minutes 3 seconds for E.ON Next. Email responsiveness is strong across both providers, with each replying to over 90% of messages within two days.
Payment options for E.ON Next include Direct Debit, Cash/Cheque, and Prepayment. Its phone lines operate Monday to Thursday from 9am to 5pm, and Friday from 9am to 4pm. So Energy accepts only Direct Debit, with customer service available on weekdays from 9am to 5pm.
Complaints and performance
In the second quarter of 2026, E.ON Next received 760 complaints for every 100,000 customers. This is much lower than So Energy, which received 1,474 complaints per 100,000 customers during the same period.
When it comes to fixing issues quickly, both suppliers perform at a similar level. E.ON Next resolved 49.61% of complaints by the end of the next working day, while So Energy resolved 49%. So Energy was slightly better at sorting out complaints within eight weeks, reaching 93% compared to E.ON Next's 89.69%.
For both suppliers, customer service was the most common reason for complaints. This made up 32.28% of complaints for E.ON Next and 31% for So Energy. Payment and billing issues were also common problems for customers of both companies.
E.ON Next wins this category because it receives far fewer complaints than So Energy, while matching its speed for quick resolutions.
Green Energy Comparison
E.ON Next
E.ON Next has a mostly renewable mix, with some fossil fuels and nuclear. It offers a specific green tariff, Next Gust, which is backed by 100% renewable electricity from UK wind generation. The supplier also installs solar panels and heat pumps to help households lower their carbon footprint. For its fixed tariffs, it makes a one-off donation to the Woodland Trust to help restore ancient woodlands.[1]
So Energy
So Energy has a mostly renewable mix, with some fossil fuels and nuclear. It includes 100% renewable electricity as standard on all its fixed-rate tariffs. The company asks its customers to vote each year on whether it should buy its renewable electricity from wind, solar, hydro, or biomass generators.[2]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | Either |
| Overall customer service | E.ON Next |
| A well-rated mobile app | So Energy |
| A greener fuel mix | E.ON Next |
E.ON Next is the stronger option with a higher Citizens Advice score and a significantly cheaper fixed tariff, though So Energy offers a cheaper variable deal.
Based on the available evidence, E.ON Next is the stronger option. It secures a higher rank with Citizens Advice and provides a significantly cheaper fixed tariff. Although the two suppliers share identical overall Trustpilot ratings and price their cheapest deals almost equally, E.ON Next demonstrates better performance across independent service metrics.
So Energy may appeal to households with a smart meter seeking a variable tariff, given its cheapest variable option undercuts E.ON Next's equivalent. Direct comparisons of their digital tools are limited, however, because E.ON Next lacks some iOS app data and So Energy's app ratings rely on very small sample sizes.
- Higher Citizens Advice score and rank
- Significantly cheaper fixed tariff option
- Higher score in the annual Which? survey
- Longer average call centre wait times
- No current iOS app rating available
- Faster average call centre wait times
- Cheaper variable tariff option
- High Google Play rating, though from a small sample
- Lower Citizens Advice score
- More expensive fixed tariff options
- Accepts fewer payment methods at a brand level
Frequently asked questions
Which is better, E.ON Next or So Energy?
E.ON Next performs better across the independent metrics we reviewed. It has a higher Citizens Advice score and offers a significantly cheaper fixed tariff, making it the stronger option for most households.
Does E.ON Next or So Energy have cheaper tariffs?
Their cheapest overall tariffs are effectively identical in price. However, E.ON Next currently offers a much cheaper fixed deal, while So Energy has a cheaper variable option.
Do customers prefer E.ON Next or So Energy?
Both suppliers hold a 4.5 out of 5 rating on Trustpilot, though E.ON Next has a slightly higher share of five-star reviews. E.ON Next also achieves a higher overall score in the annual Which? customer satisfaction survey.
Are the E.ON Next and So Energy apps any good?
So Energy has a higher rating on Google Play, though this is based on a very small number of reviews compared to E.ON Next. E.ON Next does not currently have an iOS app rating available, making it difficult to compare their Apple apps directly.
Which supplier has better customer service?
E.ON Next ranks much higher with Citizens Advice, placing 3rd compared to So Energy in 12th. However, So Energy answers phone calls faster on average.
Should I switch to E.ON Next or So Energy?
E.ON Next is the stronger choice if you want a fixed tariff or place a high value on Citizens Advice scores. So Energy may appeal to you if you have a smart meter and prefer a variable tariff, as its current variable option is cheaper.
Do E.ON Next and So Energy charge exit fees?
Yes, both suppliers include exit fees on their cheapest deals. E.ON Next charges a £200 exit fee on its cheapest 24-month fixed tariff, and So Energy charges a £190 exit fee on its cheapest 24-month variable tariff.
Can I lock in my energy prices with either supplier?
Yes, both suppliers offer fixed tariffs. E.ON Next currently offers a 24-month fixed tariff, while So Energy's cheapest fixed option has an 18-month term.
What changed this month
This month, E.ON Next's iOS app updates in last 90 days fell from 3 to 0, E.ON Next's iOS sampled neutral reviews fell from 1 to 0, and So Energy's iOS sampled neutral reviews rose from 0 to 1. There were 28 other data changes this month — see the full changelog below for details.
Data changes this month (37)
E.ON Next
- Trustpilot reviews219,212 → 225,716
- Trustpilot 5-star %74 → 75
- Trustpilot 4-star %12 → 11
- iOS app rating4.8 → no longer available
- iOS app ratings count49,000 → no longer available
- iOS app days since last update4 → no longer available
- iOS app updates in last 90 days3 → 0
- iOS sampled reviews avg stars3 → no longer available
- iOS sampled neutral reviews1 → 0
- Play Store rating4.324643 → 4.340909
- Play Store ratings count16,070 → 16,278
- Play Store days since last update5 → 4
- Play Store positive ratings %82.6 → 83.1
- Play Store negative ratings %14.2 → 13.8
- Play Store net-positive %68.4 → 69.3
- Cheapest variable tariff£1,747 → £1,560.38
- Cheapest fixed tariff£1,745.58 → £1,509.55
- Cheapest tariff£1,745.58 → £1,509.55
- Tariff count5 → 6
- Fixed tariffs available3 → 4
So Energy
- Trustpilot reviews30,220 → 30,767
- Trustpilot negative reviews replied %100 → 99
- iOS app ratings count197 → 225
- iOS app days since last update45 → 75
- iOS sampled reviews avg stars3.67 → 3.75
- iOS sampled neutral reviews0 → 1
- Play Store rating4.62 → 4.64
- Play Store ratings count127 → 138
- Play Store days since last update46 → 76
- Play Store positive ratings %92 → 91.9
- Play Store negative ratings %3.2 → 2.2
- Play Store neutral ratings %4.8 → 5.9
- Play Store net-positive %88.8 → 89.7
- Avg social media response time351 → no longer available
- Cheapest variable tariff£1,687.08 → £1,508.13
- Cheapest fixed tariff£1,828.88 → £1,734.74
- Cheapest tariff£1,687.08 → £1,508.13
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Written by
Rob Gibbs
Hi, I'm Rob, and I run Energy-Review.co.uk. I initially started this project in 2018 when I was looking to switch energy suppliers and found there wasn't a website that provided simple, data-backed reviews on all the suppliers available. Since then, I have spent a lot of time (too much, some may say!) looking at all publicly available data about each supplier and writing reviews using this information. These reviews are updated as regularly as possible, and any data is backed up by a source where necessary. I have also started writing guides on various energy-related topics, which hopefully you will find useful. If you find any issues, please use our contact form to let us know.