Who Owns Which UK Energy Supplier: Parent Companies and Groups

Almost every home in Britain buys its gas and electricity from a small number of large supply groups. Ofgem reports that six large companies hold 91% of the domestic market, and that Octopus is now the largest electricity supplier and second largest gas supplier in Great Britain¹. Uswitch, citing Ofgem, counted 17 energy suppliers operating in the UK as of April 2026². Behind many of the names on a bill sits a parent group: British Gas, for example, has Centrica as its majority owner, and EDF, the UK's fifth-largest supplier, is French-owned.

The industry's trade association, Energy UK, speaks for most of these groups. As of January 2024 its members delivered over 95% of the energy supply for 28 million UK homes and nearly 80% of UK power generation³. It is not the regulator: supply licences, rules and enforcement in England, Scotland and Wales sit with Ofgem, and Northern Ireland has its own separate market.

Not every brand a household signs up with is a supplier in law. A "white label" sells tariffs under its own name without holding a supply licence, relying on a licensed partner. Knowing which licensed company stands behind a brand matters when a complaint escalates, when a supplier fails, and when judging how much of a household's energy security rests on one company's balance sheet.

Who supplies the UK's 28 million homes, and who they answer to

The UK has 28 million homes, and heating them accounted for 18% of all UK greenhouse gas emissions in 2021⁴. Most of those homes buy both fuels from one company: in 2011 the Committee on Climate Change counted 84% of UK households (21 million) with dual-fuel energy bills. That concentration of custom is why ownership matters: a single group can hold millions of accounts.

Ofgem's retail market report describes the domestic market as dominated by six large companies with 91% market share, with Octopus now the largest electricity supplier and the second largest gas supplier in Great Britain¹. Uswitch ranks the UK's largest suppliers as follows, each figure with its own date²:

Uswitch describes Octopus as a British supplier that manages Co-op Energy's plans on its behalf⁷. For the supplier ranking and share figures in more detail, see energy supplier market share.

Every licensed supplier in England, Scotland and Wales answers to Ofgem, which describes itself as the independent energy regulator for Great Britain⁸. The UK Government holds responsibility for energy infrastructure and regulation, a point the Scottish Government makes when explaining what it can and cannot do⁹. The Energy Ombudsman handles disputes only with suppliers trading in Britain¹⁰. Northern Ireland runs a separate market with its own suppliers; see energy suppliers in Northern Ireland.

For household energy independence, the picture is one of dependence at two levels. A home relies on its supplier's company, and the country as a whole is, in the Treasury's words, "a net energy importer with a high dependence on gas and oil"¹¹. Ownership by an overseas group does not change where the gas comes from, but it does mean decisions about a large customer book can be taken far from the UK.

Energy UK: the trade association behind the suppliers

Energy UK describes itself as the trade association for the energy industry with over 100 members³. Uswitch, explaining the Energy Switch Guarantee, calls it "the trade association for the UK energy industry"¹². Its reach is wide: as of January 2024 its members delivered nearly 80% of the UK's power generation and over 95% of the energy supply for 28 million UK homes³. So Energy UK represents both generators and retail suppliers, which is why it often speaks for companies that own power stations as well as customer accounts.

End Fuel Poverty Coalition describes Energy UK as "the industry trade body which represents firms including British Gas, Scottish Power and EDF Energy"¹³. Those three names alone cover three distinct ownership structures: a UK-listed group (Centrica, for British Gas), and the retail arms of larger generating groups.

Energy UK runs several voluntary promises that its members sign:

• Energy Switch Guarantee: launched by Energy UK; all of the big six have signed up, along with several smaller suppliers¹². See the Energy Switch Guarantee.
• Vulnerability Commitment: 13 energy suppliers representing more than 95% of UK homes are signed up¹⁴.
• Winter 2024 Commitment: 15 suppliers covering almost the entire market¹⁴.

On contested issues, the association sets out an industry line. On forced prepayment meter installation under warrant, for example, End Fuel Poverty Coalition reports Energy UK's position that the warrants are a last resort¹³:

What households can take from this is that a signed commitment is a promise to the trade body and the public, not a licence condition. The firm protections a household relies on come from Ofgem's rules, covered below.

The big names under one roof: British Gas, Scottish Power and EDF Energy

Ofgem's glossary lists the historic Big Six as "Centrica plc (parent company of British Gas), E.ON UK, Scottish and Southern Energy (SSE), RWE npower, EDF Energy and ScottishPower"¹⁵. The list shows how brand and parent differ: the name on the van and the bill is British Gas, but the company that owns it is Centrica. Uswitch gives British Gas's majority owner as Centrica (UK)⁷, and describes EDF as French-owned².

Several of the names on that list no longer supply households in the same form. Customer books have moved between groups through takeovers and the supplier failures of 2021 and 2022, when 29 energy suppliers failed and nearly four million households were affected¹⁶. For the full history of each original name, see the Big Six energy suppliers; for SSE's household customers specifically, see SSE Energy Services.

Ofgem's own surveys show how the current groups compare in size of customer base. The July 2024 supplier-level findings interviewed these numbers of customers of each group¹⁷:

These are survey sample sizes, not customer numbers, but they are counted by group: Ofgem notes that E.ON / E.ON Next includes Sainsbury's Energy, and Octopus Energy includes brands managed within the group¹⁷.

When Ofgem reviewed how suppliers support customers in vulnerable situations in November 2022, it placed British Gas, Bulb, EDF, E.ON, Ovo, Scottish Power and Utility Warehouse in the first group, found to have minor weaknesses¹⁸. Profiles of individual groups are at British Gas, ScottishPower, EDF and E.ON Next.

For a household, a large parent brings scale but also concentration. If one group owns several brands, switching between those brands keeps the household with the same company behind the scenes.

White labels: how a brand can sell energy without a supply licence

Ofgem defined the model in its 2013 Retail Market Review: "A 'white label' is an organisation that does not have an energy supply licence, eg a supermarket, but works in partnership with an energy supplier to offer energy tariffs to consumers under a different brand"¹⁹. The brand handles marketing and often its own name on the customer journey, while the licensed partner supplies the gas and electricity.

In March 2016 Ofgem counted eight "white label" suppliers in Great Britain⁵. Citizens Advice, responding to Ofgem's 2015 proposals, describes white labels as organisations that do not hold a licence "but have a licensed energy supplier as a partner", with that partner "responsible for regulatory issues"²⁰.

The licensing system allows this because it regulates the supplier, not the logo. Ofgem's fuel mix guidance, for example, states that the rules are "not intended to prevent suppliers from branding their bills or other material sent to customers" or from undertaking special initiatives to raise brand awareness²¹. A licensed company may therefore present itself under a partner's brand.

Obtaining a licence is a distinct, formal step. When Tesla Energy Ventures Limited was licensed in March 2026, Ofgem announced that it had been "granted a licence authorising it to supply electricity to domestic and non-domestic consumers in Great Britain"²². A white label takes no such step itself.

In summary, the arrangement works like this:

1. The brand markets tariffs under its own name and may hold the customer relationship.
2. A licensed supplier partners with the brand and supplies the energy.
3. The licensed supplier carries responsibility for regulatory issues²⁰.
4. Ofgem's licence conditions bind the licensed supplier.

The page on white label energy brands covers the brands themselves.

White labels and their partner suppliers: why the licensed company matters

The licensed company is the one that answers for the account. Ofgem's customer satisfaction surveys put this into practice: "Subsidiary brands such as white label brands are included in the supply group that is responsible for their customer service operations"⁸. The same rule appears in the July 2024, January 2025 and January 2026 editions¹⁷, so a white label's customers are scored as customers of the partner group.

The practical consequences follow from the licence:

• Complaints and disputes: the Energy Ombudsman asks consumers to confirm that the supplier named in a dispute "matches the company name written on the account holder's bill"²⁴. It also turns cases away where the consumer "has never been a consumer of the supplier"²⁵.
• Supplier failure: when a licensed supplier fails, every brand it supplies is affected. The failures of 2021 and 2022 affected nearly four million households¹⁶; see what happens when a supplier goes bust.
• Obligations: schemes such as the Energy Company Obligation place legal obligations on larger energy suppliers²⁶, so the partner's size, not the brand's, determines whether the obligation applies.

For independence, a white label adds a layer rather than removing one. The household depends on the brand for service and on the licensed partner for supply and regulatory protection.

Transparency about brand and partner relationships: what to look for

Citizens Advice argued in 2015 that "increased transparency about the relationship between white labels and their partner suppliers is also essential"²⁰. The concern is simple: a customer who does not know the licensed company cannot easily complain, check a supplier's record, or understand what happens if it fails.

The most reliable single document is the bill. Several Energy Ombudsman pages require the complainant to confirm that the supplier's name "matches the company name written on the account holder's bill"²⁴, and its dispute service starts with the instruction: "Search for the name of your energy supplier to get started."²⁷

Points a household can find on its own paperwork:

• The legal company name on the bill, which may differ from the brand name.
• Whether a brand is described as managed by another supplier. Uswitch, for instance, describes Co-op Energy's plans as "managed by fellow British supplier Octopus on its behalf"⁷.
• Which group the brand is counted under in Ofgem's satisfaction findings, since white labels are grouped with the supplier running their customer service²³.

The electricity network is a separate company again. The Energy Ombudsman notes that a household can find its network provider through the Energy Networks Association website; network operators are not suppliers and do not change when a household switches.

For the practical steps, see how to find out who supplies your energy and who is my electricity supplier. Service scores by group are covered in energy supplier customer service ratings.

Supplier profit: about 5% after interest and tax, by Energy UK's reckoning

How much a supplier group makes is disputed, and the answer depends on which profit, which year and whose method. Carbon Brief reported in 2013 that Energy UK put energy company profits at "about five percent" on average, after interest and tax⁶. The same analysis found that the big six made just over three per cent profit on supplying energy to consumers in 2011, and 7.6 percent overall in 2011 before interest and tax were deducted⁶. The gap between those figures is largely the difference between the retail supply arm and the whole group, including generation.

More recent estimates come from campaigners. End Fuel Poverty Coalition analysis, dated September 2026, reports²⁸:

The same source gave an earlier projection of £1.74bn over 12 months; £1.74bn plus the £140m increase gives the £1.88bn figure²⁸.

In 2023 the coalition estimated that suppliers were "likely to earn 2.4% profit on every average customer's bill from 1 October", up from 1.9%²⁹. It also argued that customers would only pay less profit than before if their bill was above £4,000 a year²⁹.

Ofgem's own review of wholesale costs in the price cap found that six suppliers with 65% market share experienced an over-recovery of +£10 to +£77 per standard variable tariff electricity customer over the cap periods examined³⁰. These figures are estimates and modelled projections from different bodies, and they measure different things; they should not be read as one series. See energy supplier profits and margins.

Where the trade association fits: what Energy UK does and does not decide

Energy UK speaks for its members and organises voluntary commitments, but it holds no regulatory power. Ofgem states plainly: "Ofgem is Great Britain's independent energy regulator."³¹ Ofgem grants supply licences²², writes licence conditions, and was named by the Energy Act 2023 as the future heat network regulator for Great Britain.

The division of roles looks like this:

Some decisions that shape what a household receives come from government schemes, not the trade body. The Energy Company Obligation places legal obligations on larger energy suppliers to deliver energy efficiency measures to domestic premises²⁶, and Ofgem notes that a household can contact any obligated supplier about ECO, even if it is not their provider³⁴.

Energy UK does not decide who may supply energy, does not rule on individual complaints, and cannot fine a member. For protections that are binding, see what suppliers must do for vulnerable customers, complaining about an energy supplier and the Energy Ombudsman.

What ownership means for a household's independence

Knowing the parent company does not reduce a home's reliance on it, but it makes that reliance visible. A household on any tariff depends on its licensed supplier's solvency, on the national grid and gas network, and on a country that imports much of its gas and oil¹¹. A white label adds the brand as a further dependency. The failures of 2021 and 2022, affecting nearly four million households¹⁶, showed how quickly a customer book can move to a new company that the household did not choose. The wider question of how far a home can reduce these dependencies is covered in energy suppliers and energy independence, and the full supplier landscape in UK energy suppliers.