The Selectra verdict
The best UK energy supplier in 2026 is Octopus Energy
Octopus Energy ranks first overall on the combined 2026 signals: largest UK supplier (around 7.4 million households), top of the Citizens Advice quarterly league table, 4.8 / 5 on Trustpilot across 280,000+ reviews, 100% renewable electricity, no exit fee on any tariff, and the widest tariff line-up on the market.
For the absolute lowest bill, Octopus Tracker is the cheapest published dual-fuel deal at around GBP 1,452 / year on typical usage — roughly GBP 397 below the Q2 2026 Ofgem Price Cap of GBP 1,849. The cap is the only number that matters as a baseline: every fixed, tracker or smart tariff is judged against it.
The UK energy market in numbers
UK domestic energy market overview
- Active suppliers
- ~25
- Q2 2026 price cap
- £1849
- Cheapest dual-fuel
- £1,452
- 100% renewable share
- 8 / 12
Ofgem-licensed domestic suppliers selling new tariffs in 2026.
Typical dual-fuel direct-debit household, GB average.
Octopus Tracker, recent 12-month average. ~£397 below the cap.
Of the 12 largest UK suppliers default to 100% renewable electricity.
Best UK energy supplier by category
There is no single "best" supplier for everyone. Below is the Selectra verdict by use case, with the named tariff, the typical annual bill at Q2 2026 prices, and the headline reason in one sentence.
Octopus Energy
Octopus 12M Fixed
Typical annual bill
£1,562
23.45 p/kWh electricity
- Electricity
- 23.45p
- Gas
- 5.45p
- Exit fee
- None
Largest UK supplier in 2026 (~7.4 million households), top of the Citizens Advice league table, 4.8 on Trustpilot across 280,000+ reviews, 100% renewable electricity, no exit fee on any tariff and the widest line-up on the market (Flexible, 12M Fix, Tracker, Agile, Go, Intelligent Go, Cosy, Saver Sessions and the Outgoing export pair).
Skip if You only want a phone-first relationship with a high-street brand — Octopus is digital-first and the phone line is weekday-only.
Octopus Energy
Octopus Tracker
Typical annual bill
£1,452
21.3 p/kWh electricity
- Electricity
- 21.3p
- Gas
- 4.85p
- Exit fee
- None
Octopus Tracker reprices the unit rate daily against the wholesale market plus a fixed margin. Recent 12-month average bill on a typical dual-fuel household is around GBP 1,452 — close to GBP 400 below the Ofgem cap and the cheapest published deal in the UK market today.
Skip if You need a predictable monthly bill, you do not have a working SMETS2 smart meter, or you cannot absorb occasional cold-snap spikes.
Good Energy
Good Energy Variable
Typical annual bill
£1,812
26.4 p/kWh electricity
- Electricity
- 26.4p
- Gas
- 6.85p
- Exit fee
- None
Good Energy buys electricity directly from a portfolio of small UK wind, solar and hydro generators — not just REGO certificates bolted onto a generic supply. Independent (Cornwall-based, 1999), B Corp certified, and one of only three UK suppliers that can credibly claim "renewable by generation" rather than "renewable by paperwork".
Skip if You are optimising purely on price — Tracker, the 12M Fix and Agile are all cheaper while still 100% REGO-renewable.
Octopus Energy
Intelligent Octopus Go
Typical annual bill
£1,090
7.00 p/kWh cheap window, 24.86 p/kWh peak
- Electricity
- 7p
- Gas
- 5.74p
- Exit fee
- None
Intelligent Octopus Go charges your EV at 7.00 p/kWh in a fixed 23:30–05:30 window and schedules extra cheap sessions outside that window when wholesale prices fall. An EV driver charging 4,000 kWh / year saves roughly GBP 540 versus the same load on a standard tariff.
Skip if Your car or charger is not on the compatibility list — fall back to Octopus Go (8.50 p/kWh fixed window) or EDF GoElectric.
Octopus Energy
Cosy Octopus
- Electricity
- 13p
- Gas
- 5.74p
- Exit fee
- None
The only mass-market UK tariff with two daily cheap windows timed for heat-pump pre-heat cycles (04:00–07:00 and 13:00–16:00) at around 13 p/kWh, plus an evening peak window to deter use. Requires SMETS2 meter and a registered air-source or ground-source heat-pump install.
Skip if You still heat with a gas boiler or direct electric resistance — Cosy is engineered for heat-pump load profiles only.
EDF Energy
Simply Tracker (12M)
Typical annual bill
£1,660
23.8 p/kWh electricity
- Electricity
- 23.8p
- Gas
- 5.85p
- Exit fee
- None
EDF runs all of Britain's active nuclear reactors, declares a 91% low-carbon supply (29% renewable + 62% nuclear) and consistently tops the legacy-Big-Six Citizens Advice rankings. Simply Tracker tracks the cap downwards with no exit fee, a rare offer from a Big-Six brand.
Skip if You want the absolute lowest price (Octopus Tracker beats it by ~GBP 200) or 100% renewable supply.
Utilita
Smart Energy (prepayment)
Typical annual bill
£1,797
26.3 p/kWh electricity
- Electricity
- 26.3p
- Gas
- 6.65p
- Exit fee
- None
Utilita is the largest UK supplier specialising in smart prepayment, with around 800,000 households on the books and the most mature smart-pay-as-you-go app on the market. Tops the Citizens Advice rankings for prepayment-specific metrics and runs the Power the Fight hardship partnership.
Skip if You can move to direct debit — credit tariffs are still cheaper per kWh than the Prepayment Meter cap.
Utility Warehouse
UW Cashback Bundle
Typical annual bill
£1,780
25.9 p/kWh electricity
- Electricity
- 25.9p
- Gas
- 6.55p
- Exit fee
- None
Utility Warehouse holds a 4.7 Trustpilot score across ~65,000 reviews — one of the highest of any UK domestic supplier — and is the only UK provider bundling energy with broadband, mobile and insurance for a single monthly bill with a meaningful loyalty discount.
Skip if You only want energy and you only want the cheapest unit rate — UW is structured around the multi-service bundle.
All tariff figures verified against suppliers’ published price lists. Typical annual bills assume 2,700 kWh electricity + 11,500 kWh gas (Ofgem typical-domestic-consumption-values, GB average, direct debit, single-rate meter).
Side-by-side comparison
Compare the largest UK energy suppliers in 2026
Same six metrics for every supplier — pick the columns that matter to you and ignore the rest. Customer counts are 2026 estimates; renewable share is the Ofgem-mandated annual fuel-mix disclosure.
| Supplier | Tier | Households | Renewable | Positioning |
|---|---|---|---|---|
|
Octopus Energy
|
Largest | 7.4 m | 100% | Largest UK supplier; widest tariff line-up; Kraken platform. |
British Gas
|
Largest | 7.5 m | 76% | Centrica brand; nationwide HomeCare boiler network; high-street reach. |
E.ON Next
|
Largest | 5 m | 100% | Successor to legacy E.ON & Npower; 100% renewable electricity by default. |
|
EDF Energy
|
Largest | 5 m | 29% | Owns all UK active nuclear reactors; 91% low-carbon supply. |
OVO Energy
|
Largest | 4 m | 100% | Took over SSE retail; Plan Zero net-zero programme; REGO-matched supply. |
Scottish Power
|
Largest | 3 m | 100% | Iberdrola-owned; UK's largest onshore wind operator (Whitelee); 100% green. |
|
Utility Warehouse
|
Medium | 1 m | — | FTSE-250 multi-service bundler (energy + broadband + mobile + insurance). |
|
Utilita
|
Medium | 800 k | — | UK's largest dedicated smart-prepayment specialist; Hampshire-based. |
So Energy
|
Medium | 300 k | 100% | 10-year-old independent (now ESB Group); strong tracker line-up. |
|
Good Energy
|
Medium | 200 k | 100% | Independent (Cornwall, 1999); B Corp; direct PPAs with UK generators. |
Ecotricity
|
Medium | 200 k | 100% | Independent; pioneer of UK green energy (1995); EV-charging network. |
Outfox the Market
|
Small | 100 k | 100% | Independent online-only supplier; 100% renewable electricity. |
Customer counts are 2026 published-source estimates (supplier annual reports, Ofgem retail-market indicators, Citizens Advice supplier-performance data). Renewable share is the most recent Ofgem-mandated annual Fuel Mix Disclosure for the supplier’s standard tariff and excludes paid renewable add-ons.
How to choose
Three numbers that decide your supplier
Settle the choice in 90 seconds.
-
Your annual kWh
On a recent bill or via the Selectra calculator.
- Low
- 1.8k + 8k
- Mid
- 2.7k + 11.5k
- High
- 4.3k + 17k
kWh electricity + gas. Without real kWh, any “average bill” is ±25%.
-
Tariff type
- Variable: capped by Ofgem. Safe, no exit fee.
- Fixed 12–24M: locks the rate. Cheaper than cap.
- Tracker / Agile: follows wholesale. Cheapest in 2026.
- EV / Heat-pump: 7–13 p/kWh off-peak windows.
-
Meter + exit fee
Smart tariffs need a working SMETS2. SMETS1 = re-enrol first (2–6 weeks).
Big-Six fixes: £25–£75 exit fee. Octopus: £0.
Exit fees waived in the last 49 days of any fixed contract.
The Ofgem Energy Price Cap is the only number that matters as a baseline
Every fixed, tracker or smart tariff above is judged against this single 2026 benchmark. If a deal is below the cap, it is structurally cheaper than the default. If it is above, you are paying a premium — for service, brand, or a green PPA.
- Period
- Q2 2026
- Typical annual bill
- £1849
- Electricity
- 27.03 p/kWh
- Gas
- 6.99 p/kWh
1 Apr to 30 Jun 2026
Dual-fuel, direct debit, GB average.
+53.8p / day standing.
+32.67p / day standing.
Source: Ofgem Energy Price Cap. The cap is reviewed every three months. Fixed and tracker tariffs sit outside the cap and may be cheaper or more expensive than the headline.
The switch itself
Switch in 5 steps
Faster Switching Programme · 90 sec input · 5 working days · supply never interrupted.
-
Quote90 seconds
- In
- Postcode + annual kWh (or recent bill)
- Out
- Ranked list of cheapest tariffs for your real usage
-
Sign-up5 minutes
- In
- Bank details + current supplier name
- Out
- Confirmation email + Direct Debit mandate
-
Cool-off14 days
- In
- No action required
- Out
- 14-day window to cancel without penalty
-
SwitchUp to 5 working days
- In
- Opening meter reading (optional)
- Out
- Supply moves on the agreed switch date
-
Close-out4–6 weeks
- In
- Closing bill from old supplier
- Out
- Final balance refunded or charged within 6 weeks
Old supplier can’t block the switch unless you owe 28+ days of charges. Smart-meter data carries over. Delays beyond 5 working days = GBP 30 Ofgem compensation.
FAQ
Best UK energy supplier — frequently asked questions
Octopus Energy ranks first overall in 2026 on the combined signals — largest customer base (~7.4 million UK households), top of the Citizens Advice quarterly league table, 4.8 on Trustpilot across 280,000+ reviews, 100% renewable electricity, no exit fees and the widest tariff range. For pure price, Octopus Tracker is the cheapest published dual-fuel deal at around GBP 1,452 / year on typical usage, roughly GBP 400 below the Ofgem cap.
No. Ofgem dropped the "Big Six" label in 2024 and now refers to "large suppliers". The legacy six (British Gas, EDF, E.ON, Npower, Scottish Power, SSE) have been consolidated or rebranded — Npower folded into E.ON Next, SSE's retail book moved to OVO. The 2026 "large suppliers" group is Octopus, British Gas, E.ON Next, EDF, OVO and Scottish Power — and Octopus, an independent founded in 2015, is now the largest.
The Ofgem Energy Price Cap sets the maximum price suppliers can charge for the default (Standard Variable) tariff. It is reviewed quarterly. The Q2 2026 cap puts a typical dual-fuel household at GBP 1,849 a year on direct debit (electricity at 27.03 p/kWh + 53.80 p/day; gas at 6.99 p/kWh + 32.67 p/day). Fixed and tracker tariffs sit outside the cap and can be meaningfully cheaper.
Generally no. Octopus, E.ON Next, OVO, Scottish Power and So Energy all default to 100% renewable electricity (REGO-matched) at standard prices — there is no green premium. Specialist independents like Good Energy and Ecotricity charge a small premium because they buy through direct power-purchase agreements with named UK generators rather than the REGO market alone.
Have ready: your postcode, your annual kWh (from a recent bill or via our consumption calculator), your meter type and your bank details. The switch itself is regulated by Ofgem and takes up to 5 working days under the Faster Switching Programme. You get a 14-day cooling-off period after sign-up and your supply never gets cut. Exit fees are waived in the last 49 days of any fixed contract.
Fixing locks in today's unit rate for 12 or 24 months — protection if you expect the Ofgem cap to rise. A variable or tracker tariff lets you ride the cap down if wholesale prices fall. Selectra's default 2026 advice: Octopus 12M Fixed if you want predictability (GBP 1,562 / year typical, ~GBP 287 below cap, no exit fee), Octopus Tracker if you have a smart meter and are comfortable with daily price variation (GBP 1,452 / year typical, ~GBP 397 below cap).
The 2026 Ofgem-cap standing charge is around 53.80 p/day for electricity and 32.67 p/day for gas — a fixed daily fee covering network and policy costs, paid even on zero consumption. Most suppliers match the cap. A few prepayment and "no-standing-charge" tariffs (notably Utilita on some products) recover the cost via a higher unit rate, which is rarely cheaper unless you genuinely use little energy.
EV: Intelligent Octopus Go at 7.00 p/kWh in the 23:30–05:30 window plus app-scheduled cheap sessions — the cheapest UK overnight charging in 2026. Fallback for non-compatible cars: Octopus Go at 8.50 p/kWh fixed, or EDF GoElectric. Heat pump: Cosy Octopus is the only mass-market tariff with two daily cheap windows (04:00–07:00 + 13:00–16:00) timed for heat-pump pre-heat cycles.