EDF Energy So Energy (July 2026)
Overview
So Energy wins by offering cheaper tariffs and faster customer service response times, though EDF Energy holds a stronger Trustpilot rating.
So Energy leads this comparison by offering lower-priced fixed and variable tariffs than EDF Energy. Although EDF Energy maintains a higher Trustpilot rating across a larger customer base, So Energy records shorter call wait times, faster email responses, and higher mobile app ratings.
About EDF Energy and So Energy
Who is EDF Energy?
EDF Energy started in 2003 when the French state-owned company Électricité de France bought several UK regional energy boards. Today, it is one of the UK's largest domestic energy suppliers. It offers a wide range of tariffs for everyday households, as well as specialist options for electric vehicle owners, homes with heat pumps, and solar panel users. A key difference is its heavy use of nuclear power to back its tariffs, rather than just renewable sources like wind or solar.
Who are So Energy?
So Energy started in 2015 as a smaller supplier focused on green energy. In 2021, it joined with ESB Energy, the retail arm of Ireland's state-owned ESB Group. ESB acquired a majority shareholding in the combined company, which continues to trade as So Energy. It continues to grow as a smaller brand in the UK market. It keeps its tariff choices simple and focuses on green energy, letting customers vote on which renewable energy sources it should buy from next year. It also offers smart tariffs for electric vehicles and flexible home energy use.
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Tariffs and pricing
The lowest-priced tariff available from So Energy is a 24-month fixed deal named So Elk 24m, costing £1,638 a year. Leaving this contract early incurs a total exit fee of £190. In contrast, EDF Energy’s cheapest equivalent is the Simply Fixed 2Yr Jul28v3 at £1,693 a year. This also requires a 24-month commitment but carries a lower total exit fee of £150.
For households comparing tracker tariffs, So Energy offers the lower-priced option in this category, with its 12-month So Green Tracker tariff costing £1,744 a year. EDF Energy's Simply Tracker Sep27 has no fixed term and is priced at £1,755 a year.
Neither supplier is listed as participating in the Warm Home Discount or the Energy Switch Guarantee.
Tariff Options
EDF Energy tariffs
EDF Energy offers standard variable and fixed-term tariffs for everyday households, alongside a range of other smart and specialist tariffs for electric vehicle owners, homes with heat pumps, and solar panel users.
So Energy tariffs
So Energy offers standard variable and fixed-term tariffs for everyday households, alongside a range of other smart and specialist tariffs for electric vehicle drivers and flexible home energy use.
Customer reviews
EDF Energy achieves a Trustpilot rating of 4.8, drawn from over 234,000 reviews. Feedback frequently notes staff helpfulness and prompt response times. So Energy holds a score of 4.5 across more than 29,000 reviews; users often cite clear tariff explanations and value, though some report issues with automated phone systems.
Breaking down these ratings, 83% of EDF Energy’s reviews award five stars, while 7% give one star. So Energy’s five-star share is lower at 73%, with 12% of users leaving a one-star rating. Both suppliers actively engage with negative feedback: EDF Energy typically responds within 24 hours, whereas So Energy usually replies within 48 hours.
The latest Which? annual survey places So Energy slightly ahead with an overall score of 60, compared to 58 for EDF Energy. So Energy receives 3 out of 5 for both customer service and value for money, while EDF Energy scores 2 out of 5 in those areas. Conversely, EDF Energy performs better in the smart meters category, scoring 5 out of 10 against So Energy's 2 out of 10.
App quality and features
So Energy records higher mobile app ratings across both major platforms. It scores 4.7 on the App Store compared to EDF Energy's 4.6, and 4.6 on the Google Play Store against EDF Energy's 4.5. However, there is a substantial difference in user volume: EDF Energy has over 1,000,000 Android installs, whereas So Energy has over 10,000.
A recent sample of iOS reviews for So Energy averages 3.8 stars. Users note the clean design and straightforward navigation, although some report minor difficulties submitting meter readings. EDF Energy's recent iOS sample averages 2 stars, with several users stating that recent updates have reduced app speed and usability.
Regarding software maintenance, So Energy has recently updated both its iOS and Android applications to refine account switching and clarify energy usage graphs. While EDF Energy's Android app received a recent update, its iOS counterpart has not had a new release in over two years.
Service and support
EDF Energy scores slightly higher in the Citizens Advice ratings, achieving 2.9 out of 5 to rank 11th overall. So Energy follows closely in 12th place with a score of 2.86 out of 5. Both suppliers maintain formal vulnerability commitments registered with Citizens Advice for households requiring additional support.
Response time data favours So Energy. Its average call centre wait time is 1 minute 6 seconds, compared to EDF Energy's 2 minutes 46 seconds. Furthermore, So Energy replies to 91.3% of customer emails within two days, whereas EDF Energy manages 85.6%. So Energy also averages a social media response time of 5 minutes 51 seconds; equivalent data is unavailable for EDF Energy.
EDF Energy operates longer contact hours, open Monday to Thursday from 8am to 6pm, and Friday from 8am to 4pm. It accepts Direct Debit, Cash/Cheque, and Prepayment. So Energy is available on weekdays from 9am to 5pm and accepts Direct Debit. Neither supplier offers weekend support.
Complaints and Performance
The published complaint rates are from different quarters: So Energy recorded 1,148 complaints per 100,000 customers in Q2 2025, while EDF Energy recorded 1,528 in Q1 2025. These figures should not be treated as a like-for-like quarterly comparison.
Green Energy Comparison
EDF Energy's green energy approach
Based on Citizens Advice data from early 2026, EDF Energy's electricity mix is largely nuclear, with some fossil fuel and renewables. The supplier backs its tariffs with 100% zero-carbon nuclear electricity as standard. It notes that nuclear power produces zero carbon dioxide emissions when it is generated. It also invests in building new wind, solar, and nuclear sites across the UK.[1]
So Energy's green energy approach
Based on Citizens Advice data from early 2026, So Energy's electricity mix is a mostly renewable mix. The supplier promises that all its fixed-rate tariffs run on 100% renewable electricity. It also lets customers choose which renewable energy sources it supports by voting on the type of UK-based renewable energy generation the company invests in.[2]
Our verdict
| If you care most about | Choose |
|---|---|
| The lowest annual cost on our assumptions | So Energy |
| A marginally higher Citizens Advice score and ranking | EDF Energy |
| A well-rated mobile app | So Energy |
| A greener fuel mix | So Energy |
So Energy wins by offering cheaper tariffs and faster customer service response times, though EDF Energy holds a stronger Trustpilot rating.
So Energy leads across multiple key metrics in this comparison, making it a suitable option for households prioritising lower costs and faster support. It provides lower-priced fixed and variable tariffs than EDF Energy, alongside shorter call wait times and quicker email responses.
EDF Energy may suit households prioritising established brand size and broad customer sentiment, given its high Trustpilot score across hundreds of thousands of reviews and a marginally better Citizens Advice ranking. However, based on current pricing and contact time data, So Energy presents a stronger case for those focused on lower annual costs and faster service.
- Higher overall Trustpilot rating
- Slightly higher Citizens Advice score
- Longer weekday opening hours
- Higher-priced fixed and variable tariffs
- Longer average call wait times
- No recent updates to the iOS app
- Lower-priced fixed and variable tariffs
- Faster call centre and email response times
- Higher ratings across iOS and Android apps
- Higher exit fee on its cheapest fixed tariff
- Lower Which? score for smart meters
- Lower overall Trustpilot rating
Frequently asked questions
Which supplier is better overall?
So Energy wins this comparison because it offers cheaper fixed and variable tariffs, faster call wait times, and better app ratings. However, EDF Energy maintains a very strong Trustpilot rating and a slightly higher Citizens Advice score.
Does EDF Energy or So Energy offer cheaper fixed tariffs?
So Energy currently offers the cheaper fixed deal. Its So Elk 24m tariff costs £1,638 a year. EDF Energy's cheapest fixed option, the Simply Fixed 2Yr Jul28v3, costs £1,693 a year.
How do EDF Energy and So Energy compare on Trustpilot?
EDF Energy holds a higher Trustpilot rating of 4.8 out of 5 from over 234,000 reviews, with 83% of customers giving it five stars. So Energy scores 4.5 out of 5 from over 29,000 reviews, with 73% of customers giving it five stars.
Which supplier has the better mobile app?
So Energy scores higher on both the App Store and the Google Play Store, and updates its apps more frequently. However, EDF Energy has a much larger number of app users, with over a million installs on Android alone.
How long does it take to speak to someone at So Energy?
According to Citizens Advice data, So Energy answers phone calls in an average of 1 minute 6 seconds. This is considerably faster than EDF Energy, which takes an average of 2 minutes 46 seconds to answer.
Should I switch to EDF Energy or So Energy?
If you want the cheapest possible fixed or variable tariff and value fast call answering times, So Energy is the better choice. If you prefer a supplier with a stronger Trustpilot rating and slightly higher Citizens Advice ranking, EDF Energy may suit you better.
Are there exit fees for EDF Energy and So Energy tariffs?
Yes, both suppliers charge exit fees on their cheapest fixed tariffs. EDF Energy charges a £150 total exit fee on its Simply Fixed deal, while So Energy charges £190 on its So Elk 24m tariff.
What are the opening hours for EDF Energy and So Energy?
EDF Energy is open Monday to Thursday from 8am to 6pm, and Friday from 8am to 4pm. So Energy is open on weekdays from 9am to 5pm. Both suppliers are closed on weekends.
Do these suppliers offer variable tariffs?
Yes, both offer tracker tariffs with rates that can change. So Energy's So Green Tracker has a 12-month term and currently costs £1,744 a year, while EDF Energy's Simply Tracker Sep27 has no fixed term and costs £1,755 a year.
What changed this month
This month, EDF Energy's iOS app days since last update rose from 3 to 754, EDF Energy's cheapest tariff term changed from a variable tariff to a 24-month fixed deal, and So Energy's cheapest tariff term changed from a variable tariff to a 24-month fixed deal. There were 43 other data changes this month — see the full changelog below for details.
Data changes this month (53)
EDF Energy
- Trustpilot reviews228,447 → 234,962
- iOS app ratings count181,000 → 182,000
- iOS app days since last update3 → 754
- iOS app updates in last 90 days3 → 0
- iOS sampled reviews avg stars2.5 → 2
- iOS sampled negative reviews1 → 2
- Play Store rating4.449787 → 4.4540496
- Play Store ratings count48,436 → 49,305
- Play Store days since last update34 → 20
- Play Store positive ratings %86.9 → 87.2
- Play Store negative ratings %9.4 → 9.1
- Play Store net-positive %77.5 → 78.1
- Citizens Advice rank13 → 11
- Citizens Advice score2.6 → 2.9
- Complaints per 10,000 customers44.6 → 47.6
- Avg call centre wait time257 → 166
- Emails responded within 2 days %77.9 → 85.6
- Cheapest variable tariff£1,584.14 → £1,754.76
- Cheapest fixed tariff£1,671.75 → £1,692.77
- Cheapest tariff£1,584.14 → £1,692.77
- Cheapest tariff exit fee£0 → £150
- Cheapest tariff termvariable → 24 months
- Cheapest fixed tariff exit fee£100 → £150
- Cheapest fixed tariff term12 months → 24 months
- Tariff count6 → 4
- Fixed tariffs available4 → 2
- Variable tariffs available1 → 2
So Energy
- Trustpilot reviews29,346 → 29,771
- iOS app ratings count165 → 170
- iOS app days since last update8 → 22
- iOS sampled reviews avg starsnow available (3.8)
- iOS sampled positive reviews0 → 3
- iOS sampled negative reviews0 → 2
- Play Store rating4.6237626 → 4.6
- Play Store ratings count105 → 118
- Play Store days since last update24 → 22
- Play Store negative ratings %4.8 → 4.3
- Play Store neutral ratings %3.8 → 4.3
- Play Store net-positive %86.5 → 87
- Citizens Advice rank11 → 12
- Citizens Advice score2.7 → 2.86
- Complaints per 10,000 customers64.2 → 57.1
- Avg call centre wait time90 → 66
- Avg social media response timenow available (351)
- Emails responded within 2 days %86.8 → 91.3
- Cheapest variable tariff£1,582.51 → £1,744.17
- Cheapest fixed tariff£1,670.24 → £1,637.61
- Cheapest tariff£1,582.51 → £1,637.61
- Cheapest tariff exit fee£0 → £190
- Cheapest tariff termvariable → 24 months
- Tariff count7 → 5
- Fixed tariffs available6 → 3
- Variable tariffs available1 → 2
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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.