Compare Big Six Energy Suppliers in the UK

The UK energy market has seen many changes in recent years. But the Big Six energy suppliers still give gas and electricity to millions of homes. These large energy firms are some of the most well-known energy providers in the United Kingdom. They offer different tariffs, help with renewable energy, and have many types of customer service.

This guide tells you who the Big Six are. It shows how they match up on energy prices, how green they are, and what people think about their service. You will see why it is good to compare energy prices before you decide to change to a new provider.

Who Are the Big Six Energy Suppliers?

The “Big Six” are the biggest energy companies in the UK. They have the most customer numbers and the largest market share in the retail market. Even though the energy crisis has changed a lot in the market, these companies still lead the way.

These companies give power to most UK households. But there are also smaller energy companies. Some of these are Good Energy, Utility Warehouse, and Sainsbury’s Energy. They all try to get customers, so this is why they compete.

How Do Their Energy Prices Compare?

Each supplier has its own mix of fixed, variable, and green energy tariffs. The prices go up or down with the energy price cap from Ofgem. Some have lower standing charges. Others give you better value if you use smart tariffs.

Figures are based on the average dual fuel tariff for July 2025. The price you pay can be different, as it depends on your area and the tariff you have.

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Who Offers the Best Customer Service?

When you talk about energy customers, good service is very important. The latest numbers about complaints performance and scores from Which? and Citizens Advice show this.

Octopus Energy stands out as the top company for customer service. In recent years, Scottish Power and British Gas have not done as well. Their customer service ratings have been lower.

Which Supplier Is the Greenest?

Many UK energy suppliers say they use renewable sources, but how do they really compare when it comes to making an impact in the real world?

If you want to lower your carbon footprint and help green energy, Scottish Power and Octopus are good choices.

What Else Should You Consider When Choosing a Supplier?

Besides price and renewable energy, there are some other things that change value:

Energy Usage Tools

Some suppliers, such as Octopus and OVO, give you real-time usage data. They also offer smart tariffs and energy reports. These things help you improve your energy efficiency.

Rewards & Perks

• OVO Energy: Some tariffs from OVO Energy come with free boiler cover. This can help if you need to get your boiler fixed. It is a good way to feel safe about your home heating.
• Octopus Energy: You get access to time-of-use pricing with Octopus Energy. It lets you save money when you use power at different times of the day. There are also EV rewards for those who drive electric cars.
• British Gas: British Gas gives you HomeCare bundles for boiler and heating cover. This can help you stay warm and fix problems faster. It’s one way they make sure your home is safe.

The plans from british gas, ovo energy, and octopus energy can be good if you want extra cover for your boiler or new ways to save money.

Billing & Payment Options

All suppliers give the choice to use monthly direct debit. You can also get paperless billing from them. They help with smart meters as well. Some of them will let you pay in advance and offer budgeting tools.

How Has the Market Changed in Recent Years?

Before the energy crisis, smaller providers had more of the market. But since 2021, many of them have left. Now, the Big Six hold more power in the market.

According to the Office of Gas and Electricity Markets (Ofgem):

• British Gas is now the largest supplier of electricity.
• The top 6 provide power to over 75% of the UK population.
• People are moving more towards renewable electricity now. There is also a big focus on cost savings by using digital tools.

It is now more important than ever to compare energy prices. This is true if your fixed deal with them has finished.

FAQs About the Big Six Energy Suppliers