Who are the UK's energy companies?

You’ve probably already heard of the big six, but there are dozens of UK energy companies out there. Here’s a rundown of who they are, which ones are British-owned and how to choose a supplier.

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In this guide:

  • How many UK energy companies are there?

  • Who are the UK's big six energy suppliers?

  • Which energy suppliers are British-owned?

  • Gas and electricity companies UK – who specialises in green power?

  • Who are the cheapest gas and electric suppliers in the UK?

  • Does it cost money to switch UK energy suppliers?

  • How to switch UK energy companies

How many UK energy companies are there?

The number of companies that provide electricity to UK customers fluctuates as companies enter and exit the market for whatever reason (such as going out of business). As of January 2021 there are over 80 energy suppliers on the market – many of these are smaller suppliers who have recently entered the market, so expect a lot volatility: rising wholesale energy prices, price caps and changes in consumer behaviour can all put smaller gas and electric providers out of business in the UK, with fresh start-ups to replace them.

The good news is that if your energy company does go out of business, Ofgem will step in to ensure your supply isn’t interrupted, and will place you with another energy supplier (who you’re free to leave) automatically.

Who are the UK's big six energy suppliers?

Roughly 70% of UK households get their electricity supply from one of the ‘big six’. These are:

Updated 21 December 2020
Provider UK electricity market share* Nationality of parent companyDescription
British Gas 18.23%UK Owned by parent company Centrica, British Gas is the UK’s biggest energy supplier overall, serving over 11 million homes.
SSE/OVO 15.34% (combined)UK SSE trades under different names depending on the region, including SWALEC and Scottish Hydro. It serves around five million customers in the UK, providing electricity as well as boiler and heating services and broadband. In 2019, OVO Energy acquired all of SSE’s domestic energy business.
E.ON 12.04%German E.ON is the world’s largest utility service owned by investors, serving over 26 million customers.
EDF 10.73%French The largest producer of electricity in the UK, EDF is French-owned. It was created in 2003 and is known for its low-carbon electricity sources including nuclear power plants and wind farms.
ScottishPower 9.11%Spanish ScottishPower serves just over 2.8 million electricity customers (plus 1.9 million gas). It’s a subsidiary of Spanish company Iberdrola, headquartered in Bilbao. This company is leading the way with wind power, and all fixed price electricity tariffs are now 100% green.
npower 6.53%German In January 2019, the previously German-owned company announced it was being bought by E.ON – a merger meaning the energy market is now effectively the “big five”. Having originally remained a separate business, npower is slowly starting to be incorporated into E.ON proper – customers looking to switch to npower will instead be directed to E.ON’s website instead.

*According to Ofgem, Q2 2020

These long-running businesses formed after the passing of the 1989 Electricity Act, which smoothed the path to privatisation in the energy sector. 

Which energy suppliers are British-owned?

The big six may be the best-known options on the market, but there are dozens of other UK energy suppliers out there. This is good news for consumers, as the increased competition provides more choice than ever when seeking out a great deal on electricity and gas. Smaller companies also tend to put a focus on customer service to set them apart from the bigger names. 

If you wish to support a wholly British-owned company, then look out for the following names when searching:

Updated 21 December 2020
Avro 40,000 (elec), 30,000 (gas)Nuneaton A Warwickshire-based company that began trading in 2015, Avro works to keep prices low by reducing overhead costs. Expect simple packages with competitive prices.
British Gas 11,000,000+ Staines-upon-Thames Britain’s largest energy company.
Bulb 1,500,000London Bulb is a fast-growing energy provider that focuses on simplicity. It only offers one variable tariff, making things easy to understand, and it focuses on low-cost, green energy.
Co-op Energy 300,000London Part of the Midcounties Co-operative, Co-op Energy is the only UK supplier that’s owned by its customers. It started up in 2010 and is now operated in partnership with Octopus Energy. Its Community Power tariff is powered by electricity from local suppliers, who generate green energy from wind, sunlight and water.
Ecotricity 200,000+Stroud Ecotricity lays claim to being “Britain’s greenest energy company”. It’s been generating renewable electricity since 1995 and is branching out into “green gas” generation too.
Green Energy UK 20,000+Ware Green Energy UK is a small but unique energy supplier, with an obvious focus on renewable green energy. Unlike most other green energy suppliers across the UK, its plans offer both exclusively renewable gas and electricity.
Octopus 1,500,000London Octopus is one of the biggest UK electricity suppliers outside the big six, expanding rapidly with its long-term investment in carbon-friendly energy sources. It promises better customer service than the big six and is a major investor in solar farms.
OVO 1,500,000Bristol Another investor in eco-friendly energy sources, Ovo Energy offers 100% renewable tariffs. Based in Bristol, England, it began trading in 2009. Ovo publishes an annual environmental impact report, keeping its sources transparent. Its purchase of SSE has propelled OVO into the big six list of energy suppliers.
SSE 3,500,000PerthSee above.
Utility Warehouse 600,000+ Colindale This multi-utility provider supplies UK households with a full range of services – in addition to offering gas and electricity it also supplies landline, mobile telephone, and broadband in heavily discounted bundles.

These represent just a few of the options out there. Although it’s easy to get caught up with the big six, it’s worth exploring some of these smaller UK companies as well to find the best tariff for your household.

Gas and electricity companies UK – who specialises in green power?

Are you interested in reducing your carbon footprint? Many of the suppliers we’ve mentioned above specialise in green power, sourcing their electricity from wind farms and solar panels. While it used to be a niche offering, 100% renewable tariffs are increasingly common and affordable. 

This includes the big names like EDF as well as smaller suppliers like Octopus and Ovo. To find a green electricity tariff, you can use our energy comparison tool and look for tariffs that come with a ‘green’ label. 

Who are the cheapest gas and electric suppliers in the UK?

With so many options on the market, how can you get started with a comparison? The first thing is to remember that the big six aren’t always the cheapest, nor will they offer the best customer service. In many cases, smaller suppliers from Avro to Octopus will offer cheaper rates.

As wholesale energy prices fluctuate, the cost of gas and electricity will change accordingly. As a result, there isn’t a single cheap energy supplier for everyone. 

To get started with a comparison, you need to think about your household consumption, the type of tariff you’d prefer, and whether you want a green plan. If you use both gas and electricity, dual-fuel tariffs usually offer the best value. 

If it’s been some time since you’ve switched suppliers, you’re probably currently on your supplier’s standard variable tariff. This will be the most expensive type of plan, which is why it’s a good idea to compare your options. You will most almost certainly find a better deal and save a significant sum simply by switching.

Does it cost money to switch UK energy suppliers?

Not if you’re on a standard variable plan – in most cases, you’ll only be charged a fee if you’re on a fixed-term deal with the fees clearly stated in the contract. You should have been made aware of these when signing up for the deal – exit fees typically cost £30-60 per fuel, and while many fixed deals come with these conditions, an increasing number don’t, so check with your supplier if you’re not sure. 

Note, if you enter the final 49 days of your contract, then you shouldn’t be charged a fee as you’ve entered the ‘switching window’, a period where you can set up and transfer to another deal without being liable for any penalties.

Even if you’re not currently looking to change supplier – or are still in a period where you’re liable for an early-exit fee, it’s still a good idea to use an energy price comparison tool to find out which tariffs are available in your postcode. Not only will you keep abreast of changes in the market, you may even find a deal so good it’s worth taking the hit of early exit fees to benefit from.

How to switch UK energy companies

Current Ofgem data shows that between October 2019 and October 2020, 5.8 million electricity customers and 4.4 million gas customers switched suppliers in the UK. 1.3 million electricity and 1 million gas customers switched to small or medium providers during January to October 2020.

It’s easy to make the switch. All you’ll need is your postcode. Use an online tool to compare the best deals on offer, answering a few basic questions. If you have a recent energy bill to hand, you can input the information about your household’s typical energy usage for more tailored results. 

You’ll see a list of results. In addition to pricing, you should think about factors like:

  • Customer service reputation

  • Green energy tariffs

  • Type of meter (smart, Economy 7)

  • Type of plan (Fixed, variable, prepayment)

You’ll have a 14-day cooling-off period after you’ve made your selection, so you’ll be able to change your mind without penalty. 

There are dozens of energy companies in the UK, both big and small. It’s well worth comparing your options to find the best tariff.

Last updated: 21 December 2020