Most Expensive Energy Supplier UK 2026

📊 2026 Ofgem Price Cap Summary Q1 2026 (Jan–Mar): £1,758/year typical household | Electricity: 27.35p/kWh | Gas: 5.74p/kWh Q2 2026 (Apr–Jun): £1,641/year — DOWN 7% from Q1 | Potential saving: ~£117/year vs Q1 Best Fixed Deal Available: ~£1,632/year (Octopus / Co-op 12M Fixed) — already BELOW the Q2 cap

With UK household energy bills still significantly above pre-crisis levels, knowing which energy supplier is charging you the most — and why — is one of the most valuable pieces of consumer knowledge in 2026. Whether you're asking "who is the most expensive energy provider UK?", "is British Gas the most expensive?", or simply looking for the best energy supplier to switch to, this guide gives you the complete, Ofgem-verified answer.

In this guide, we rank the top 10 most expensive energy suppliers UK for 2026, explain exactly why standard variable tariffs (SVTs) cost so much more than fixed deals, and show you how much you could realistically save by switching today.

•       Section 1: Top 10 Most Expensive Energy Suppliers UK 2026 — Full Ranking

•       Section 2: Who Is the Most Expensive Gas and Electricity Supplier in the UK?

•       Section 3: Why Are Some Energy Providers More Expensive Than Others?

•       Section 4: Energy Prices by Region — Where You Pay the Most

•       Section 5: How Much Could You Save? Real Switching Estimates

•       Section 6: The Best Energy Supplier to Switch To in 2026

•       Section 7: How to Switch Away From an Expensive Supplier — Step by Step

•       Section 8: Frequently Asked Questions

Image 2: Top 10 Most Expensive Energy Suppliers UK 2026 Ranking Table | switchsquid.com

The most expensive energy supplier UK in 2026 depends on your tariff type. Customers on Standard Variable Tariffs (SVTs) with mainstream suppliers — including British Gas, EDF Energy, ScottishPower, and OVO Energy — are paying at or close to the Ofgem price cap ceiling (~£148–149/month). Meanwhile, specialist green suppliers such as Eko Energy and Good Energy charge even more due to the genuine cost of sourcing 100% renewable and green gas.

Full Supplier Cost Comparison Table

#	Supplier	Monthly Cost	Annual Cost	Tariff Type	Status
1	Eko Energy (Green Gas SVT)	~£175/mo	~£2,100/yr	Standard Variable (Green Gas)	MOST EXPENSIVE
2	Good Energy SVT	~£162/mo	~£1,947/yr	Standard Variable	VERY EXPENSIVE
3	ScottishPower SVT	~£149/mo	~£1,785/yr	Standard Variable (SVT)	HIGH
4	OVO Energy SVT	~£149/mo	~£1,785/yr	Standard Variable	HIGH
5	EDF Energy SVT	~£149/mo	~£1,785/yr	Standard Variable (SVT)	HIGH
6	British Gas SVT	~£148/mo	~£1,776/yr	Standard Variable (SVT)	HIGH
7	E.ON Next Fixed	~£139/mo	~£1,668/yr	12M Fixed + Boiler Cover	COMPETITIVE
8	Shell Energy Fixed	~£138/mo	~£1,656/yr	12M Fixed	COMPETITIVE
9	Co-op Energy Fixed	~£136/mo	~£1,632/yr	12M Fixed	CHEAPEST FIXED
10	Octopus Energy Fixed	~£136/mo	~£1,632/yr	12M Fixed · No exit fee	BEST VALUE

⚠️ Tariff Type Matters More Than Supplier Brand The single biggest driver of whether you are paying the most or least for energy in 2026 is whether you are on a Standard Variable Tariff or a proactively chosen fixed deal — not which supplier you're with. A British Gas 12-month fixed deal (£139/mo) is cheaper than an Octopus Energy SVT (£148/mo).

Visual: Monthly Cost by Supplier & Tariff

Image 3: Monthly Energy Cost Comparison Chart — UK Suppliers 2026 | switchsquid.com

Who is the most expensive gas and electricity supplier in the UK depends on whether you combine dual fuel or look at each separately:

Most Expensive Electricity Supplier UK 2026

On a Standard Variable Tariff basis, ScottishPower and EDF Energy top the list for electricity-only unit rates, both charging at the Ofgem price cap of 27.35p/kWh. For specialist suppliers, Eko Energy charges the highest electricity unit rate at approximately 29–31p/kWh due to green sourcing premiums.

Most Expensive Gas Supplier UK 2026

For gas supply, Eko Energy (formerly Green Energy UK) is unambiguously the most expensive gas and electricity supplier — its 100% green gas, sourced from organic waste via biomethane injection, carries a significant cost premium over conventional natural gas. Good Energy is second most expensive. For the Big Six, ScottishPower and British Gas are broadly at parity at the SVT cap rate of 5.74p/kWh.

Most Expensive Dual Fuel Supplier

ScottishPower, EDF, and British Gas are effectively tied as the most expensive energy provider for dual fuel customers on SVTs, at approximately £1,785/year. The cheapest dual fuel arrangement in 2026 is from Octopus or Co-op at £1,632/year — a difference of £153/year.

The SVT Trap: Standard Variable vs Fixed Tariff

Image 4: SVT vs Fixed Tariff Cost Comparison Explainer | switchsquid.com

Key Insight: Approximately 19 million UK households remain on Standard Variable Tariffs. This means the majority of the country is paying the maximum permitted unit rate every quarter. Every single one of these households could save £100–917/year by proactively choosing a fixed deal.

Understanding why the most expensive energy provider charges what it does helps you make smarter decisions. The price difference between suppliers isn't arbitrary — five structural factors drive higher bills.

1. Wholesale Energy Procurement Strategy

~40% of your energy bill is wholesale energy cost — what your supplier paid to buy gas and electricity in advance. Suppliers who locked in wholesale contracts at the 2026–23 peak (following Russia's invasion of Ukraine) may still be partially reflecting those costs. More agile suppliers using dynamic hedging secured lower long-run wholesale rates.

2. Green Gas & Renewable Premium

Suppliers offering 100% green gas — sourced from biomethane, anaerobic digestion, or organic waste — pay a genuine premium above conventional gas market rates. Eko Energy (formerly Green Energy UK) and Good Energy pass this cost on, making them the most expensive energy suppliers in the UK in absolute terms, but for verifiable environmental reasons.

3. Network Distribution Charges (DNO Costs)

Suppliers pay Distribution Network Operators (DNOs) to transport energy to homes — and these charges vary significantly by region. North Wales, Merseyside, and parts of Scotland have the highest distribution costs. These costs are passed directly to customers and represent 20–25% of a typical energy bill.

4. Operating Overheads: Legacy vs Digital-First

Legacy suppliers like British Gas, EDF, and ScottishPower carry large operational footprints: thousands of engineers, legacy billing infrastructure, high-street presences, and traditional call centres. Digital-first challengers like Octopus Energy use technology to dramatically lower cost-to-serve — savings passed on as lower unit rates. This operational gap is one reason why is British Gas the most expensive is such a frequently Googled question.

5. Exit Fees & Tariff Lock-In

Some fixed-rate deals carry exit fees of £30–£75 per fuel (up to £150 dual fuel). While these may appear competitive on headline unit rates, the true cost of being locked in — particularly if cheaper deals emerge — must be factored in. Always check exit fee terms before switching. SVTs have no exit fees by Ofgem rules.

💡 Key NLP Terms for This Topic: SVT / Standard Variable Tariff: Default tariff placed on when a deal ends — tracks Ofgem cap. Always the most expensive ongoing option. Ofgem Price Cap: The quarterly ceiling Ofgem sets on the unit rate SVT customers can be charged. NOT a cap on your total bill. Unit Rate: Pence per kWh — the per-unit cost of gas and electricity you actually consume. Standing Charge: A fixed daily charge (pence/day) regardless of usage. Currently 57–61p/day for electricity under Ofgem Q2 2026. REGO Certificates: Renewable Energy Guarantees of Origin — proof that electricity supplied comes from a certified renewable source.

Even on the same tariff with the same supplier, where you live significantly affects your energy bill. Ofgem permits suppliers to vary unit rates by distribution region, creating meaningful price differences across England, Scotland and Wales.

Region	Electricity Unit Rate	Gas Unit Rate	Standing Charge	Cost vs Average
North Wales & Mersey	Highest in UK	~5.95p/kWh	~63p/day	+8% above avg
North Scotland	Very High	~6.02p/kWh	~65p/day	+10% above avg
South Western	High	~6.14p/kWh	~62p/day	+7% above avg
London / South East	Average	~5.74p/kWh	~61p/day	At average
East Midlands	Low	~5.42p/kWh	~58p/day	−5% below avg
Yorkshire	Lowest in UK	~5.38p/kWh	~57p/day	−6% below avg

These regional differences mean national average comparisons can be misleading. Always use a postcode-specific comparison tool — like SwitchSquid's free energy comparison service — to see real local prices before switching.

🗺️ Key Takeaway: North Wales, Merseyside, and North Scotland consistently show the highest energy unit rates in the UK. Households in Yorkshire and the East Midlands pay up to 10% less per unit than those in higher-cost regions.

Image 5: Energy Switching Savings Estimates by Household Size UK 2026 | switchsquid.com

The gap between the most expensive energy supplier and the most competitive deal available in 2026 is substantial. Switching from an SVT to the cheapest fixed deal could save the average UK household £126–£400 per year, with the most engaged switchers saving up to £917 annually according to industry comparison data.

April 2026 Price Cap Drop — Act Now

From 1 April 2026, the Ofgem price cap drops to £1,641/year — a 7% reduction saving SVT customers approximately £117/year vs Q1. However, the cheapest fixed deals are already at £1,632/year — meaning switching to a fixed deal still beats the new cap by ~£9/year. More importantly, fixed deal customers are protected from any future cap increases until their deal expires.

Fixed Rate vs. SVT: The Decision Framework

•       Fix if: Analysts predict the cap will rise (Q3 2026 onwards) — locking in now protects you.

•       Stay variable if: Multiple cap drops are forecast — SVT customers benefit automatically from every reduction.

•       Current consensus (March 2026): Fixed deals at £1,632/yr still marginally beat Q2 cap and provide price certainty through winter 2026–27.

If you're currently with the most expensive energy provider, the question becomes: who is the best energy supplier to switch to? The answer depends on your priorities, but our analysis of Ofgem data, Trustpilot ratings, Citizens Advice supplier scores, and current tariff pricing points to the following recommendations:

Best Energy Supplier for Price: Octopus Energy

Consistently ranked as the best energy supplier UK for price and customer service. Octopus Energy's 12-month fixed deal at ~£136/month (£1,632/year) is the cheapest available in March 2026. It carries no exit fees, a 5-star Trustpilot rating, and a top Citizens Advice supplier star rating. For most UK households, Octopus is the standout best energy provider in 2026.

Best for Green Energy: Good Energy or Ecotricity

If 100% genuine renewable electricity and green gas matter to you, Good Energy (REGO-certified) and Ecotricity (wind-powered) are the leading options. Bear in mind these green credentials come at a price premium — expect to pay 10–15% more than the cheapest mainstream fixed deals.

Best for Customer Service: E.ON Next

E.ON Next consistently scores highest among large suppliers for customer satisfaction, with strong Ofgem complaints data and prompt resolution times. Their 12M fixed deal at ~£139/month is competitive and includes optional boiler cover.

Best for Smart Tariffs: Octopus Agile / Go

Octopus Energy's smart tariffs — Agile Octopus and Octopus Go — offer dynamic or off-peak pricing for EV owners and smart meter users. Households with flexible usage patterns can save significantly more than standard tariff comparisons suggest.

🔗 Compare Energy Deals Now: Use SwitchSquid's free comparison tool to see the best energy supplier for your postcode: switchsquid.com/compare-home-energy

Switching your energy supplier is fully protected under UK law. Under the Energy Switch Guarantee, the process takes an average of 5 working days, your supply is never interrupted, and Ofgem protects your credit balance if your supplier goes bust. Here's exactly how to do it:

1.     Gather your current bill details. Find your annual kWh usage for gas and electricity, your current unit rate (p/kWh), and current standing charge. These are on any recent bill or in your online account.

2.     Compare using an accredited tool. Use SwitchSquid or another Ofgem-accredited comparison service with your postcode and usage data. Compare dual-fuel and separate tariffs — sometimes buying gas and electricity from different suppliers is cheaper.

3.     Check exit fees. If you're on a fixed deal, check your terms. You can switch fee-free within 49 days of your deal ending. On a Standard Variable Tariff (SVT), there are no exit fees at all.

4.     Accept the new tariff. Sign up online. Your new supplier handles the entire transfer — you don't need to contact your old supplier at all.

5.     Take a meter reading on switch day. Submit this to both your old and new supplier to ensure your final bill is accurate and you're not overcharged.

6.     Set a renewal reminder. Fixed deals expire. Set a calendar alert for 49 days before your deal ends so you can compare and switch again before automatically defaulting back to an expensive SVT.

📌 Related SwitchSquid Guides (Internal Links): →  Cheapest Energy Supplier UK 2026 — Find the cheapest deals by region and usage →  Who Is Cheaper Than British Gas? — Full comparison with British Gas alternatives →  Cheapest Dual Fuel Energy Supplier UK — Save more with bundled gas & electricity →  Fixed vs Variable Energy Tariff Guide — Which is right for your situation in 2026? →  Worst UK Energy Suppliers 2026 — Who to avoid based on complaints data →  Cheapest kWh Electricity UK — Find the lowest unit rates available

Q: Who is currently the most expensive energy supplier in the UK?

A: For mainstream suppliers on Standard Variable Tariffs, ScottishPower, EDF Energy, and British Gas are the most expensive, each at approximately £148–149/month (£1,785/year) in Q1 2026. Among specialist suppliers, Eko Energy is the most expensive energy provider overall at ~£175/month due to 100% green gas sourcing costs. The cheapest available deals in March 2026 come from Octopus Energy and Co-op at ~£136/month.

Q: Is British Gas the most expensive energy supplier?

A: British Gas is one of the more expensive mainstream suppliers when comparing Standard Variable Tariffs, at approximately £148/month. However, it is not the single most expensive — EDF Energy and ScottishPower charge comparably, and green suppliers like Eko Energy and Good Energy charge significantly more. British Gas does offer fixed deals that are more competitive than its SVT, so the answer depends heavily on which tariff you're comparing.

Q: Who is the most expensive gas and electricity supplier in the UK?

A: For 100% green gas and electricity combined, Eko Energy (formerly Green Energy UK) is the most expensive supplier in the UK at approximately £2,100/year. For conventional gas and electricity, ScottishPower, EDF, and OVO Energy are among the priciest on Standard Variable Tariffs at around £1,785/year each.

Q: What is a Standard Variable Tariff and why is it so expensive?

A: A Standard Variable Tariff (SVT) is a supplier's default tariff — the one you're automatically placed on when a fixed deal expires or when you move into a new property. It tracks the Ofgem price cap and rises or falls with quarterly cap reviews. Because the cap is set at the maximum suppliers can charge, SVT customers are always paying the ceiling rate. Fixed deals can typically undercut this by 5–15%.

Q: Will energy prices fall in 2026?

A: The Ofgem price cap fell from £1,758 to £1,641 on 1 April 2026 — an 11% reduction versus April–June 2026. The Q3 2026 (July–September) cap will be announced by 27 May 2026. Wholesale gas price futures suggest prices may edge upward into winter 2026–27, making fixed-rate tariffs particularly attractive from Q2 2026 onward.

Q: Which is the best energy supplier to switch to in 2026?

A: Octopus Energy leads on both price and customer service in 2026, with a 12-month fixed deal at ~£136/month and zero exit fees. E.ON Next is best for customer service among larger suppliers. Good Energy and Ecotricity lead for verified green credentials. For smart meter and EV users, Octopus's Agile and Go tariffs offer the highest potential savings.

Q: Can I switch suppliers if I'm in debt to my current supplier?

A: Yes, in most cases. If you have owed money for fewer than 28 days on a credit meter, switching is normally permitted. Prepayment meter customers can usually switch with debts under £500. Your existing debt will be added to your final bill, not transferred to the new supplier. Larger debts may require a repayment plan first — contact your supplier for options.

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

A: In March 2026, the cheapest dual-fuel fixed tariffs are from Octopus Energy and Co-op Energy, both at approximately £136/month (£1,632/year). These represent the best value if you're looking to switch from the most expensive energy provider. Check SwitchSquid's comparison tool for real-time personalised prices at your postcode.