Energy Supplier Profits and Margins Explained

A household energy supplier's profit on a capped default tariff is one named line in the bill: EBIT, meaning how much the supplier makes before interest or tax¹. It sits alongside wholesale costs, network costs, policy costs, operating, debt and industry costs, headroom, the levelisation allowance and VAT in the way the regulator builds the cap². That line is thin. Suppliers were reported to be earning 2.4% profit on every average customer's bill from 1 October 2023, up from 1.9% before³. A tracker of tariff changes put the figure at an average £64.70 of profit per customer per year in September 2026, up by £4.70 per customer, with projected 12 month profits for all energy suppliers combined reaching £1.88bn, an increase of £140m⁴.

Those retail figures are far smaller than the numbers most often quoted for "energy company profits". The larger totals, £6bn banked by energy firms in the first six months of 2026, worth over £200 of profit for every household in the country, and around £125 billion in profits on UK operations by 30 energy companies since 2020, cover generation, networks and trading as well as the business that sends a household its bill⁵. Around a quarter of an energy bill is taken in profit by the range of firms involved in the industry, and of 30 firms monitored, 26 made a profit over five years⁶. Conflating the two, the supply margin and the industry total, is the single most common error in this subject.

The supply business itself is not reliably profitable. Energy UK, the trade body, states that profit margins are small and less than those in most other industries such as supermarkets, and that many suppliers in recent years have been loss-making⁷. Both statements can be true at once: a slim, regulated retail margin, and very large earnings elsewhere in the chain.

The published figures, and why they disagree

There is no single official number for supplier profit. Different bodies measure different things, over different periods, and the gap between them is the story.

The regulator's own historic breakdown shows how volatile the retail line is. Across the six large suppliers in 2015, profits on domestic electricity sales fell from £544.0m in 2014 to £128.7m in 2015, while profits on domestic gas supply rose from £615.7m to £845.0m, giving total domestic supply profits of £973.8m against £1,159.7m the year before. In the same period the average non-domestic electricity profit margin fell from 2.0% to 1.0%⁸. A single year moved domestic electricity profit by a factor of four.

Earlier still, Citizens Advice found that suppliers had raised prices by 37 per cent over three years, eight times faster than earnings, alongside a 75% rise in energy firms' profits⁹. That 2013 figure is the sort of headline that shapes public expectation, and it is worth noting it is more than a decade old and predates the price cap.

Where the regulator gathers its own evidence it does so from a limited set of firms: a wholesale costs review received data from 11 suppliers¹⁰. Sector totals published by campaign groups and trackers are estimates built on tariff modelling, not audited accounts, and should be read as reported figures rather than settled ones.

EBIT: the profit line inside the price cap

The price cap, set by Ofgem, limits how much a supplier can charge for each unit of electricity and gas and the daily standing charge. It does not limit the total bill: the more energy used, the higher the bill². It applies where a customer has not signed up for a fixed-term contract, and a separate cap is set for each of the 14 supply regions of Great Britain¹¹. It came into force at the beginning of 2019 and is revised each quarter¹¹.

Ofgem lists the cap's components as wholesale costs, network costs, policy costs, operating costs, EBIT, headroom, the levelisation allowance and VAT, with VAT at 5% on gas for 1 October 2026 to 31 March 2027². Wholesale costs are what a supplier pays to buy energy; operating, debt and industry costs are what it pays to run the business¹. Network costs are the next most important component after wholesale, making up almost 30% of the total¹¹. The levelisation allowance exists to make sure prepayment and Direct Debit customers pay the same standing charge².

Because EBIT is expressed as a share of the capped cost stack, it rises and falls with the cap itself. That is why the reported margin moved from 1.9% to 2.4% at a cap change, and why one analysis concluded that customers would only pay less profit to energy firms than before if their bill were above a staggering £4,000 a year³. A higher cap mechanically enlarges the cash value of a percentage allowance.

The cap's headline "typical household" figure is an illustration, assuming consumption of 2,500 kWh for electricity and 9,500 kWh for gas¹². Actual profit per customer depends on how much that household buys and how it pays.

For April to June 2026 the capped rates were reported as 24.67p per kWh and 57.21p per day for electricity, and 5.74p per kWh and 29.09p per day for gas, with an average 2-3 bedroom house paying by direct debit spending £1,641 a year on gas and electricity¹⁴. Ofgem has confirmed that the cap for 1 April to June 2026 would fall by 7%, and estimates suggest it is expected to stay roughly the same until the end of the year¹⁵.

What drives the margin up and down

Three things move supplier profit more than anything a household does.

1. The wholesale price. Wholesale energy prices, which energy firms pay, determine the cap¹⁶. Rapid increases from mid-2021 led to a 54% increase in the cap in April 2022¹². A larger cost stack carries a larger cash EBIT for the same percentage.
2. Cost control against the allowances. The cap sets allowances for operating, debt and industry costs¹. A supplier that runs below them keeps the difference; one that runs above them, typically through bad debt or service failures, does not.
3. Tariff mix. Fixed tariffs are not protected by the cap². Two fixed offers analysed in May 2023, an OVO 1 Year Fixed and an SSE 1 Year Fix, were estimated to generate average profit per customer of £484 and £469 respectively¹⁷. That is an order of magnitude above a capped default tariff's per-customer figure.

Policy also moves the number. The government cut policy costs in April 2026 by ending a levy-funded energy efficiency scheme and shifting funding for the largest renewable generation support scheme to general taxation¹¹. That reduced the bill without touching supplier earnings, which is a reminder that a falling cap does not necessarily mean a falling margin.

Great Britain, Northern Ireland and the regional picture

The EBIT allowance described above is a feature of the Great Britain price cap. It sets maximum unit prices and daily standing charges for customers in each energy supply region of Great Britain, with a separate cap for each of the 14 regions applying throughout the region and no breakdown below regional level¹¹.

Northern Ireland works differently. Energy prices were not capped there, and suppliers have the flexibility to set their tariffs independently to reflect their costs of operating¹⁸. There is therefore no published EBIT allowance to point to for a Northern Ireland household bill, and no quarterly regulator-set ceiling of the Great Britain kind. Readers comparing the two markets should look at energy suppliers in Northern Ireland and Northern Ireland gas tariffs rather than assume the cap figures translate.

Within Great Britain, Scotland and Wales sit inside the same cap framework, with regional differences in unit rate and standing charge rather than in the profit allowance. For the South Wales region on a single rate, capped rates were published as 26.33p per kWh and 57.84p per day in September 2026¹⁹. Welsh Government guidance gave the cap as 27.69p per kWh for electricity with a 54.75p daily standing charge for 1 January to 31 March 2026¹⁵. These figures are for different regions and periods and are not directly comparable. Households in Scotland can check the same framework through energy suppliers in Scotland.

The rules that govern what a supplier may earn

Supplier profit is bounded by licence rather than by any profit cap as such. Energy suppliers can be fined if they do not follow the standard licence conditions²⁰. Ofgem has stated that it expects suppliers to take their obligations seriously and comply with business-as-usual practices in line with the standard licence conditions, and that it will be:

Three further rules matter to households directly:

• Reselling. A landlord or site owner cannot profit from the energy they resell: they can only charge the same price they paid²¹. The same rule is stated for residents of alternative homes such as park homes.
• Community supply. Under the Community and Smaller-scale Electricity Supplier Services Scheme, an eligible licensed supplier must return any money raised through the sale of energy under such a tariff to the community or smaller-scale energy site, save for a permitted fee²².
• Undercutting is allowed. Suppliers can charge less than the capped rates², so the cap is a ceiling on price, never a floor under profit.

Where a household believes it has paid too much or been treated badly, the route is the supplier's complaints process and then the Energy Ombudsman, which is independent of the energy company and free of charge²³. That is set out in more detail on complaining about an energy supplier.

What supplier profit means for a self-sufficient household

Every pound of EBIT on a bill is a pound paid for the service of being supplied. Reducing it has only two mechanisms available to a household: buying fewer units from a supplier, or moving the units it does buy onto a cheaper contract. Only the first changes the structural position, because the cap limits unit rates and the standing charge but not the total bill¹⁶, and the standing charge is payable whatever the consumption.

Self-generation cuts the purchased volume. The measure used for this is grid electricity independence, or self-sufficiency, defined as the percentage of electricity consumed in the property over a year which is met by either behind the meter solar or electrical energy storage, that is, the fraction met by self-consumed electricity²⁴. Exported surplus flows the other way under the Smart Export Guarantee, with electricity suppliers paying new small-scale energy producers for excess electricity from homes and businesses put back into the grid²⁵.

What remains is substantial, and worth stating plainly. A connected home still pays network costs, which make up almost 30% of the capped bill¹¹, and policy costs and VAT, none of which self-generation removes while the connection exists. It still pays a daily standing charge whether or not it draws a unit. It still depends on a licensed supplier as the counterparty for both import and export, on a regulator to set the ceiling, and on wholesale markets it does not control: prices have been reported as high due to conflict in the Middle East²⁶. Households are free to use whichever energy supplier they choose²⁷, and that choice is the main lever most have over the margin they pay, but it is a choice between suppliers, not an exit from supply. The most honest way to read the profit figures is as the price of that remaining dependence: small per unit on a capped tariff, large in aggregate across the industry, and reducible mainly by needing fewer units in the first place.

For the wider market context, see UK energy suppliers and energy suppliers and household energy independence.