Compare all 21 UK energy suppliers — the Big Six and beyond, ranked by tariff, price, and customer score.
All UK Energy Suppliers
Compare all 21 UK energy suppliers — the Big Six and beyond, ranked by tariff, price, and customer score.
Suppliers We Compare
As well as the big names you know, we help you discover new brands that can offer you more.
The Big Six Energy Suppliers in the UK (2026)
The term 'Big Six' refers to the six largest providers by market share. The group has changed significantly since 2019 — npower merged into E.ON and SSE's domestic customers moved to OVO Energy.
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Big Six Supplier Profiles
A closer look at each major UK energy supplier — what they do best and where they sit in the market.
Octopus Energy
UK's largest electricity supplier (24% market share). Known for Agile, Tracker, and Cosy tariffs. Consistently highest customer satisfaction of any major supplier.
British Gas
UK's largest gas supplier, established 200+ years ago. Offers PeakSave (50% off Sundays), Hive smart home ecosystem, and broad boiler cover packages.
E.ON Next
Absorbed npower in 2021. Invested over £3.5bn in UK renewables since 2009. 100% renewable electricity across all tariffs with flexible fixed-rate deals.
OVO Energy
Acquired SSE's 1.5M domestic customers in 2020. Integrates carbon tracking and smart home automation. 100% renewable electricity as standard.
EDF Energy
French state-owned. UK's largest zero-carbon electricity generator via nuclear fleet and offshore wind. Competitive fixed tariffs for smart meter customers.
ScottishPower
Spanish-owned (Iberdrola). Generates 100% of own electricity from wind farms. Particularly cost-competitive in Scotland and Northern England.
Smaller & Independent UK Energy Suppliers
Independent & Specialist Suppliers
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UK Energy Price Cap — April 2026 Update
Do big energy suppliers offer better value than smaller ones?
Current Price Cap Rates (April–June 2026)
Rates vary by region. Always compare using your postcode for an accurate quote.
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How to Compare and Switch Energy Suppliers
Under the Energy Switch Guarantee, your switch completes within 5 working days.
Find Your Annual Usage
Check your latest bill for your annual kWh figure. No bill? Switch estimates usage from your home size.
Enter Your Details
Your postcode determines exact regional unit rates from every supplier serving your area.
Compare Tariff Types
Fixed vs variable, exit fees, contract length, payment method. Switch shows the full picture with total annual cost.
Select and Confirm
Choose your deal. 14-day cooling-off period. Your old supplier continues until the switch completes.
Switch Completes
Within 5 working days. Take a meter reading on switchover day. Entitled to £30 if switch takes longer.
Fixed vs Variable Tariffs — Which Is Better in 2026?
Our recommendation: if a fixed deal is priced more than 3–5% below the current price cap with no exit fee, it is worth taking.
Fixed Rate
Unit rate locked for 12–24 months. Protected from price cap rises. Usually £30–£75 per fuel exit fee. Best for budget-conscious households expecting prices to rise.
Standard Variable (SVT)
Rate follows Ofgem price cap quarterly — currently £1,641/year. No exit fees. Best for flexibility and those expecting prices to fall.
Green Energy Suppliers UK
Green does not always mean expensive. Octopus Energy's standard tariff is both cheap and 100% renewable-backed. Here is what to check.
REGO Certificates
Proof your electricity comes from renewable sources. Look for REGO-backed tariffs — available from Octopus, E.ON, and 100Green at no premium.
Green Gas Certification
Biomethane backed by Green Gas Certificates from REA. Rarer than green electricity — offered by Ecotricity and Good Energy.
Additionality
Does your spend fund new renewable generation or just buy existing certificates? The best green tariffs invest directly in new wind, solar, and hydro capacity.
Frequently Asked Questions — UK Energy Suppliers
How many energy suppliers are there in the UK?
There are 21 licensed energy suppliers serving domestic customers in the UK as of March 2025, according to Ofgem. The number fell sharply after the 2021 energy crisis, when over 30 smaller suppliers exited the market.
Who is the cheapest energy supplier in the UK right now?
Who is the UK's largest energy supplier?
Can I switch energy supplier if I'm in debt?
How long does switching energy supplier take?
Will switching energy supplier affect my supply?
Who is my energy supplier?
Compare All UK Energy Suppliers on Switch
Switch covers every licensed UK energy supplier — big, small and green. Enter your postcode and start comparing in under 60 seconds.
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