All UK Energy Suppliers

Compare all 21 UK energy suppliers: the Big Six and beyond, ranked by tariff, price, and customer score.

All UK Energy Suppliers

Q: Who is the cheapest energy supplier in the UK right now?

As of March 2026, Octopus Energy's standard fixed tariff is among the cheapest available for a typical household, approximately £1,514/year against the April 2026 cap of £1,641.

Q: Who is the UK's largest energy supplier?

Octopus Energy became the UK's largest electricity supplier in 2023 and holds 24% market share as of 2026. British Gas is the largest gas supplier.

Q: Can I switch energy supplier if I'm in debt?

Yes, if your debt is under £500 and you have been in arrears for less than 28 days. Under Ofgem rules, debt should not be a barrier to switching to a cheaper deal.

Q: How long does switching energy supplier take?

Under Ofgem's current rules, a switch must be completed within five working days. You also have a 14-day cooling-off period to cancel for free.

Q: Will switching energy supplier affect my supply?

No. Your gas and electricity are delivered through the same pipes and cables regardless of who supplies you. Only the billing party changes.

Q: Who is my energy supplier?

If you do not know your current supplier, check a recent energy bill, your property's meter, or use the Find My Supplier tool on the Energy Networks Association website.

Compare all 21 UK energy suppliers: the Big Six and beyond, ranked by tariff, price, and customer score.

Compare All Energy Suppliers

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.

#	Supplier	Market Share	Ownership	Best For	Rating
1	Octopus Energy	24%	British	EV tariffs, smart tech, green energy, competitive pricing	★★★★★
2	British Gas	22%	British (Centrica)	Brand trust, boiler cover, half-price Sunday electricity	★★★☆☆
3	E.ON Next	16%	German (E.ON SE)	Fixed tariffs, renewables investment, SME-friendly	★★★★☆
4	OVO Energy	12.6%	British (OVO Group)	Smart home tech, carbon tools, SSE customer legacy	★★★☆☆
5	EDF Energy	10.5%	French (govt-owned)	Nuclear green energy, competitive fixed deals, EV tariffs	★★★★☆
6	ScottishPower	8.2%	Spanish (Iberdrola)	100% wind-generated electricity, competitive in Scotland	★★★☆☆

← Swipe to see all columns →

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

As of March 2025, Ofgem listed 21 licensed energy suppliers in the UK. Beyond the Big Six, several independent and challenger suppliers offer competitive tariffs, often with lower prices and stronger customer service ratings.

Independent & Specialist Suppliers

Supplier	Speciality	Best For
Outfox Energy	Fixed-rate deals, price transparency	Budget-conscious households
100Green	100% renewable gas and electricity	Fully certified green energy
Good Energy	Green tariffs, solar export payments	Solar panel owners
Ecotricity	Green gas (biomethane), wind power	Hardcore eco-consumers
Utilita Energy	Prepayment meters, Pay As You Go	Prepayment customers
Utility Warehouse	Bundle: energy + broadband + mobile	One bill for multiple services
Co-op Energy	Community energy, managed by Octopus	Co-op members
So Energy	Fixed tariffs, UK customer service	Personal phone support
Fuse Energy	App-first, competitive fixed deals	Mobile-first energy users
Sainsbury's Energy	Loyalty rewards, Nectar points	Sainsbury's shoppers
E (Gas & Electricity)	Prepayment tariffs, Birmingham-based	Pay-as-you-go in the Midlands

← Swipe to see all columns →

Business Energy Suppliers UK

Not all suppliers serve both homes and businesses. The UK business market is served by around 35 licensed suppliers in 2026, including mid-market and industrial-only providers.

Big Five Business Suppliers

British Gas Business, EDF Energy, E.ON Next, ScottishPower, and OVO/SSE Energy Solutions.

Cheapest-Tier Suppliers (2026)

Yu Energy, SEFE Energy, Pozitive Energy, and Crown Gas & Power.

Renewable Business Specialists

Ørsted, Drax, Bryt Energy, and Good Energy Business.

Bundle Providers

Utility Warehouse Business: energy, broadband, and mobile on one bill.

Not Price-Cap Protected

Business energy contracts are not protected by Ofgem's price cap. Prices are negotiated directly between supplier and customer, so comparison and renewal timing are critical to cost management.

UK Energy Price Cap: April 2026 Update

The Ofgem energy price cap is set at £1,641 per year for the period 1 April to 30 June 2026 (for a typical household paying by direct debit). This is a 7% reduction from the previous quarter's cap of £1,758.

The price cap does not limit the total amount you pay, it limits the maximum unit rate (pence per kWh) and daily standing charge that suppliers can charge. If you use more than the Ofgem 'typical' consumption, your bill will exceed the cap figure.

Do big energy suppliers offer better value than smaller ones?

The largest UK energy suppliers (British Gas, E.ON, EDF, and ScottishPower) accounted for over 70% of domestic customers a decade ago. Today that share is below 50%, with challenger suppliers winning on both price and service. Octopus Energy and OVO have each grown by over 3 million customers since 2020.

Smaller suppliers are not inherently riskier: Ofgem's Supplier of Last Resort scheme means your supply is protected if a provider fails. What smaller suppliers can offer is more competitive unit rates, because they carry lower overheads and marketing costs.

Price, not brand size, should drive your choice. Switch compares tariffs from 30+ UK suppliers side by side so you can see exactly who offers the best deal for your postcode and usage.

Current Price Cap Rates (April to June 2026)

Rates vary by region. Always compare using your postcode for an accurate quote.

Fuel Type	Unit Rate (from April 2026)	Standing Charge
Electricity	~24.50p per kWh (national avg)	~61p per day
Gas	~6.24p per kWh (national avg)	~31p per day

← Swipe to see all columns →

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 to 5% below the current price cap with no exit fee, it is worth taking.

Fixed Rate

Unit rate locked for 12 to 24 months. Protected from price cap rises. Usually £30 to £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.

Compare Energy Deals Now Compare Home Energy Expert Help: 01926 942125

Latest from our experts

Broadband15 min read

900Mbps broadband deals UK September 2026: ranked by first-year cash

Ranked 900Mbps and 1Gbps UK broadband deals for September 2026 by first-year cash, with postcode coverage, price rises, upload speeds and honest 900 vs gigabit guidance.

Mobile16 min read

50GB SIM only deals UK September 2026: ranked by 12-month cash

Compare exact 50GB SIM only deals in the UK for September 2026, ranked by 12-month cash. See iD, Lebara and Lycamobile prices, contract terms and coverage checks.

Mobile11 min read

Cheapest phone deals UK September 2026: ranked by 24-month cash

Cheapest phone deals UK September 2026 ranked by 24-month cash. Currys Galaxy A16 SIM-free £139 + Talkmobile Flex 30GB £6.95 = £305.80. iD A16 10GB £423.36 with rises.

Broadband12 min read

300Mbps broadband deals UK September 2026: ranked by first-year cash

300Mbps broadband deals UK September 2026 ranked by first-year cash. Community Fibre London £267; Virgin M250 £311.88; NOW FF300 336; Virgin M350 347.88.

Mobile16 min read

40GB SIM only deals UK September 2026: ranked by 12-month cash

40GB SIM only deals UK September 2026: iD Mobile £7 on 12 months (£84/year) leads. VOXI social £8, spusu £9.90, SMARTY £10. Ranked by 12-month cash from retailer shops.

Mobile15 min read

30GB SIM only deals UK September 2026: ranked by 12-month cash

30GB SIM only deals UK September 2026: Talkmobile £6.95 (£83.40/year) leads. iD £7 (£84). Lycamobile intro £115. Ranked by 12-month cash from retailer shops.

Broadband15 min read

150Mbps broadband deals UK September 2026: ranked by first-year cash

150Mbps broadband deals UK September 2026 ranked by first-year cash. Community Fibre London from £220.20; Virgin M125 £287.88; TalkTalk £320; EE/BT £361.88.

Mobile20 min read

5GB SIM only deals UK September 2026: ranked by 12-month cash

5GB SIM only deals UK September 2026: Lebara 12-month £4.50 (£54/year) leads on lebara.co.uk. Lycamobile £3.50 then £5, spusu £4.90 unlimited calls. Talkmobile 5GB tile dropped — not on retailer shop.