How SwitchInsights reviewed So Energy: we looked at price versus the confirmed Q4 cap, the Trustpilot and Citizens Advice record, smart meter support and exit-fee terms. We update it whenever Ofgem moves the cap or So Energy changes a tariff.
The short version
So Energy prices above the confirmed Q4 cap right across its fixed range, and holds a 4.4 out of 5 Trustpilot rating. Its cheapest fix, So Kookaburra Loyal 24m, sits £27 a year above the cap, and So Kookaburra 24m is £50 above it. The Loyal rate is open to anyone switching in, despite the name. But cheaper peers exist. Fuse Energy's 18-month fix comes in well under So Kookaburra 18m, so anyone chasing the absolute cheapest sticker will find it elsewhere.
Where So Energy earns its place is a mix of Trustpilot standing (4.4 out of 5 from around 31,500 reviews, Sunday Times Best Places to Work three years running) and stability (traded continuously since 2015, backed by Ireland's state-owned ESB since 2021, which is now reviewing a sale). On the Citizens Advice supplier star rating it is weaker, 11th of the 16 rated suppliers and below the 3.4 median. For households who value that mix over price-hunting, So Energy is a defensible pick. For everyone else, at least run the Loyal 24m and 18-month fix past the tariff tracker before switching away.
What is So Energy?
So Energy is a UK domestic energy supplier founded in 2015 by Simon Oscroft and Charlie Davies, both former Macquarie energy traders. It went to market as a challenger brand selling 100% renewable electricity to households frustrated with the Big Six, and grew steadily rather than aggressively - avoiding the loss-leading pricing that collapsed around thirty rival suppliers in the 2021-22 wholesale gas crisis (Ofgem supplier-of-last-resort record).
Ownership changed materially in August 2021, when Ireland's state-owned electricity company ESB took a 75% majority stake and merged its own UK retail arm, ESB Energy, into So Energy. The two co-founders kept a combined 10% stake and stayed on the executive team; Charlie Davies is CEO today. So Energy serves around 300,000 UK homes, its own published figure, from London. The 100% renewable electricity promise carried through the merger, though as with every UK supplier the underlying electricity mix depends on grid conditions rather than direct farm-to-plug supply.
From start-up to ESB majority-owned green supplier
2015Founded on 100% renewable electricity
Simon Oscroft and Charlie Davies launch So Energy in London, funded initially by their own savings and small angel cheques. The pitch is straightforward: renewable electricity at prices that undercut the Big Six's premium green tariffs.
2021ESB takes 75% majority stake
Ireland's state-owned ESB acquires a controlling 75% stake and merges its UK arm, ESB Energy, into So Energy. The founders retain a combined 10% and stay on the executive team. So Energy keeps trading through the 2021-22 wholesale gas crisis while around thirty rival suppliers collapse into administration.
2026~300,000 customers, Sunday Times Best Places to Work three years running
So Energy serves around 300,000 UK homes from London. Charlie Davies leads as CEO. Trustpilot rating 4.4 from ~31,500 reviews; Sunday Times Best Places to Work (Big Company) for the third year running.
So Energy tariffs and prices versus the confirmed Q4 cap
Ofgem confirmed the Q4 2026 price cap on Wednesday 26 August, with new rates running from 1 October to 31 December. The confirmed Q4 cap is £1,723 a year for a typical dual-fuel Direct Debit household on Ofgem's current TDCV standard (2,500 kWh electricity, 9,500 kWh gas), a rise of £60 on the Q3 figure of £1,663 on the same TDCV. On the older 2023 TDCV (2,700 kWh electricity, 11,500 kWh gas) the confirmed Q4 cap is £1,935, up £73 on the Q3 £1,862 headline. The tables below benchmark against the £1,723 confirmed figure.
| Tariff | Term | Electricity | Gas | Typical annual cost |
|---|---|---|---|---|
| Q4 2026 cap (Ofgem confirmed) | Benchmark | 26.32p/kWh, 54.83p/day | 7.97p/kWh, 29.68p/day | ~£1,723/year |
| So Flex (default variable tariff) | Variable | Tracks the Q4 cap rate | Tracks the Q4 cap rate | ~£1,723/year |
| So Kookaburra 12m | Fixed | 28.05p/kWh, 55.41p/day | 9.34p/kWh, 29.49p/day | £1,891/year |
| So Kookaburra 18m | Fixed | 29.61p/kWh, 47.30p/day | 9.00p/kWh, 24.45p/day | £1,854/year |
| So Kookaburra 24m | Fixed | 26.74p/kWh, 56.71p/day | 8.34p/kWh, 30.21p/day | £1,773/year |
| So Kookaburra Loyal 24m | Fixed | 26.33p/kWh, 56.71p/day | 8.21p/kWh, 30.21p/day | £1,750/year |
| So EV | EV time-of-use | 7.50p/kWh off-peak (midnight-5am); daytime rate varies by postcode | Not applicable | Not published without a postcode |
Against the confirmed Q4 cap of £1,723, every So Energy fix now prices above it. So Kookaburra 24m sits £50 above the cap, So Kookaburra 18m £131 above, So Kookaburra 12m £168 above, and So Kookaburra Loyal 24m, the cheapest of the four, £27 above it. The name suggests a renewal-only rate, but So Energy quotes it to new customers as well. The comparison table in the next section shows how that stacks up against the cheapest fix on the market. So EV is an electricity-only time-of-use rate for EV households running a separate gas deal or an all-electric home; So Energy publishes the off-peak rate but not the daytime rate or standing charge without a postcode, so we do not quote an annual cost for it. So Energy markets the fixed range as So Fixed; it also offers So Green Tracker and the currently paused So Unique, neither priced here.
Exit fees: So Kookaburra 12m charges £71 per fuel to leave early, £142 total for a dual-fuel household. The 18m, 24m and Loyal 24m fixes charge £90 per fuel. On every So Energy fixed tariff, the 12-month included, the fee is waived in the final 49 days. So EV carries its own exit fee - check at quote stage.
So Energy vs Octopus Energy, E.ON Next and Fuse: fixed deal comparison
The table below lines up So Energy's nearest-term fixes against the cheapest live fixed deal on the tracker, Fuse Energy, priced on the same typical dual-fuel usage against the confirmed Q4 cap. E.ON Next and Octopus Energy are left out of the price table because neither publishes a fixed rate for every region without a postcode, so the regional midpoint used for So Energy and Fuse is not available for them. All annual costs are the midpoint across the 14 GB regions.
| Supplier | Tariff | Term | Typical annual cost | Vs Q4 cap | Exit fee |
|---|---|---|---|---|---|
| Q4 2026 cap | Benchmark | N/A | ~£1,723/year | - | - |
| Fuse Energy | Fixed (18m) v4 | 18 months | ~£1,642/year | -£81/year | £50/fuel |
| So Energy | So Kookaburra Loyal 24m | 24 months | ~£1,750/year | +£27/year | £90/fuel |
| So Energy | So Kookaburra 18m | 18 months | ~£1,854/year | +£131/year | £90/fuel |
| So Energy | So Kookaburra 24m | 24 months | ~£1,773/year | +£50/year | £90/fuel |
| So Energy | So Kookaburra 12m | 12 months | ~£1,891/year | +£168/year | £71/fuel |
Fuse Energy's 18-month fix undercuts the Q4 cap, the most aggressively priced deal on the tariff tracker for a typical dual-fuel household. So Energy's 18-month option lands £131 above the cap, and its cheapest fix, So Kookaburra Loyal 24m, £27 above it. So Energy prices above the cap on every fixed deal, so the main gap between So Energy and Fuse is headline sticker price, not service model or product depth. Figures checked 12 October 2026.
So Energy customer service and Trustpilot record
Trustpilot and Citizens Advice: So Energy's Trustpilot rating sits at 4.4 out of 5 from around 31,500 reviews, behind E.ON Next's 4.5 out of 5 from over 237,000 reviews and Octopus Energy's 4.8 out of 5 from over 840,000, all checked on Trustpilot in October 2026. On the Citizens Advice supplier star rating, So Energy scored 2.85 out of 5 for April to June 2026, 11th of the 16 rated suppliers and below the 3.4 median.
So Energy billing and the app
So Energy runs phone and live chat support. The billing platform is straightforward, not innovative, lacking the granular usage dashboards Octopus Energy's Kraken platform provides.
Which So Energy tariffs work with a smart meter
So Energy smart meter support covers SMETS2 devices at no extra cost, feeding accurate monthly billing across every tariff. There is no half-hourly or agile-style smart tariff, unlike Octopus Energy's Agile and Cosy range, so on the fixed tariffs it improves billing accuracy without unlocking an off-peak rate.
So Energy pros and cons
What works
- Trustpilot rating of 4.4 out of 5 from around 31,500 reviews
- ESB-backed since 2021 and traded continuously through the 2021-22 crisis - majority-owned by Ireland's state utility, which began a divestment review in July 2026
- Sunday Times Best Places to Work (Big Company) three years running - service culture reflected in the Trustpilot score
- Phone and live chat support, SMETS2 smart meters fitted free
Worth knowing
- Cheapest fix on the market undercuts every So Energy deal (Fuse 18m)
- Even So Kookaburra Loyal 24m, the cheapest fix it sells, prices around £27 a year above the confirmed Q4 cap
- Only one time-of-use option (So EV, midnight-5am) - no half-hourly or agile-style tariff, unlike Octopus Energy
- Billing platform is straightforward but lacks the granular usage dashboards Kraken-based rivals offer
Verdict by household type
The right call depends on the usage pattern, and in particular on how much of the bill is gas.
Typical dual-fuel household
Fix elsewhere for the sticker-price saving. Fuse Energy's 18-month fix at around £1,642 undercuts the confirmed Q4 cap and every So Energy fix. So Kookaburra Loyal 24m (~£1,750) is the cheapest deal So Energy sells and anyone switching in can take it, but it still prices £27 above the cap and trails Fuse. Check how much you could save on the SwitchPilot Tariff Tracker.
Low-use flat
Favour the default tariff over any fix. Standing charges make up a larger share of a low-use bill, and the So Energy standing charge sits close to or above the cap on most fixes, and every fix prices above the cap anyway.
High-gas home
Prioritise the lowest gas unit rate on the market over the So Energy unit rate specifically. So Kookaburra 12m's gas rate of 9.34p/kWh is the highest we track on our 7 October 2026 scrape, against 7.92p/kWh on both EDF's Simply Tracker and ScottishPower's Cap Tracker, a gap that compounds on high winter usage.
See So Energy's current rates for your postcode
So Energy quotes its tariffs by postcode, so the rates on this page will not match every address. If a So Energy fix is on your shortlist after reading the verdict above, their own tariff page is the place to confirm what you would actually be offered, and the exit fee is waived in the final 49 days of any fixed term.
See So Energy tariffs →Frequently asked questions
Is So Energy any good in 2026?
Solid on Trustpilot, above the cap on price. So Energy scores 4.4 out of 5 on Trustpilot from around 31,500 reviews and is Sunday Times Best Places to Work three years running. On price, its cheapest fix, So Kookaburra Loyal 24m, sits £27 above the confirmed Q4 cap, and So Kookaburra 24m is £50 above it. The Loyal rate is open to new customers too, despite the name. Cheaper peers exist - Fuse Energy runs around £81 below the cap - so So Energy rates better on Trustpilot than on price.
Is So Energy cheap right now?
Not the cheapest. So Kookaburra 24m prices around £50 a year above the confirmed Q4 cap, So Kookaburra 18m around £131 above and So Kookaburra 12m around £168 above, and So Kookaburra Loyal 24m, the cheapest of the four and open to anyone switching in, around £27 above it. Fuse Energy's 18-month fix at around £1,642 prices below every So Energy fix.
So Energy vs E.ON Next: which is cheaper?
E.ON Next does not publish a fixed rate for every region without a postcode, so the regional midpoint used for So Energy and Fuse is not available for it. Compare both for your own postcode on the SwitchPilot tariff tracker. So Energy's edge is its Trustpilot rating, not price.
So Energy vs Octopus Energy: which is cheaper?
Octopus Energy's dual-fuel fixed tariffs are not in our daily scrape for every region, so we have no verified annual figure to rank it against So Energy on price. Compare both for your own postcode on the SwitchPilot tariff tracker. Octopus does offer half-hourly tariffs, Agile and Cosy, that So Energy does not.
Does So Energy support smart meters?
Yes, So Energy fits SMETS2 smart meters at no extra cost. So EV offers a cheaper off-peak rate between midnight and 5am; on the fixed tariffs a smart meter improves billing accuracy without unlocking an off-peak rate.
What is So Energy's Trustpilot score?
So Energy's Trustpilot rating sits at 4.4 out of 5 from around 31,500 reviews, behind E.ON Next's 4.5 from over 237,000 reviews and Octopus Energy's 4.8 from over 840,000, all checked in October 2026.
How to switch to So Energy
Ofgem requires suppliers to complete a switch within five working days, with no interruption to supply, and you can cancel within 14 days if you change your mind. Compare So Energy's current rate against the wider market on the SwitchPilot tariff tracker first, since other suppliers are sometimes cheaper.
So Energy exit fee: what does it cost to leave?
So Kookaburra 12m charges £71 per fuel to leave early, £142 total for a dual-fuel household. The 18 and 24-month fixes charge £90 per fuel, £180 total. On every So Energy fixed tariff, the 12-month included, the fee is waived in the final 49 days.
How financially stable is So Energy?
So Energy has traded continuously since 2015. On 24 July 2026 So Energy confirmed that "our parent company, ESB, has initiated a process to evaluate potential divestment options for So Energy" following a strategic review. On 6 September 2026 Sky News reported that EDF Energy was one of a small number of parties in talks to acquire So Energy, with at least one rival bidder, and Reuters reported the same the next day, citing a source. Neither company has announced a deal, so nothing is settled and ownership could change during a fixed term. That is worth knowing rather than worrying about: where a supplier sells its customer book, Ofgem expects the transfer to be as seamless as possible, and expects domestic customers on a fixed contract to keep their existing terms and tariff for the rest of that contract. It remains a mid-sized supplier, worth weighing alongside price when choosing a fixed term.
*Affiliate disclosure - the So Energy link above is an affiliate link. SwitchInsights earns a commission when readers switch through it, at no extra cost to you. That commission has zero influence on what we write. This review still sends a typical dual-fuel household to a cheaper fix elsewhere, and we earn nothing for that advice - the box above is there for readers who want So Energy's own postcode quote after reading the verdict, not a recommendation to switch to it.