Cheapest Energy Supplier UK 2025 – Real Cost Comparison

With the cost of energy going up and down because of changes in market conditions, many people in the UK want to know who will be the cheapest energy supplier in 2025. It does not matter if you are on a fixed tariff, a variable energy tariff, or if you use a prepayment meter. This guide will help you learn more. You will get to see what deals are out there right now. This guide shows you how to avoid high exit fees. It will help you check your energy use so you do not pay too much.

We look at some top suppliers like Octopus, British Gas, OVO, and a few new ones. We use energy price cap data from July 2025. The way each tariff works and the real unit rates are compared. This can help you see how the price cap and different tariff options might change the energy price you pay.

What Is the Current Energy Price Cap?

As of 1 July 2025, Ofgem has set the new energy price cap.

From July, the price cap will help keep your energy price under control. The energy price cap is there so you do not pay too much for your energy. Ofgem uses this price cap to make sure people in the UK get a fair energy price and are not overcharged.

• A typical home that uses both gas and electricity and pays by Direct Debit spends about £1,568 each year.
• This number is based on using 2,700 kWh of electricity and 11,500 kWh of gas.

Prices can change based on your energy supplier. Where you live can also make a difference. Your usage is another thing that affects how much you pay. If you have a smart meter, this can change the price too.

Cheapest Fixed Tariffs – July 2025

A fixed tariff keeps the unit rates the same for over 12 months. This means the rate you pay for electricity does not go up, even if the energy market changes. With a fixed tariff, you do not need to worry about your electricity bills suddenly getting more expensive. This helps you feel safe, because you will know what you have to pay every month. A tariff like this gives people peace of mind, as it helps their bills stay steady.

All of these plans are cheaper than the price cap. But only Octopus has no exit fees. This means you can change your plan if the energy market changes.

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Cheapest Variable Tariffs

A variable energy tariff can rise or fall with the market. It always stays under the Ofgem price cap. This kind of tariff is easy to change. You are not locked in and you do not need to pay exit fees. But remember, the prices can go up or down at any time.

These tariffs are a good choice for people who are not sure what energy prices will be in the future. They also work well for those who want to leave quickly if better energy deals come up.

Cheapest Prepayment Tariffs

If you use a prepayment meter, the prepayment cap will apply. Ofgem sets this limit. The cap for a prepayment meter is usually a bit higher than the cap for direct debit.

July 2025 Prepayment Price Cap:

• £1,522 a year on average
• Electricity: about 23.20p for every kWh
• Gas: about 6.10p for every kWh

Suppliers with Low Prepayment Rates:

• E.ON Next Pay As You Go
• Octopus Pay In Advance
• Utilita Smart Prepay
• Shell Energy PayG Plan

Some let you put in money using a mobile app. You can also do this in stores. Many of these work with smart meters now. This lets you check your energy usage right when it happens.

Green Energy Deals – Are They Still Cheaper?

Yes — green energy now often costs less, or about the same, as a regular plan. All the main companies now use green energy in their standard offers. You can also pick green upgrades if you want.

If you have an electric vehicle or you use solar panels, you should look for the tariffs that give a smart export guarantee. It is also good to see if there are any lower rates at night when you can charge your car.

Special Discounts, Cashback & Extras

Some suppliers give extra benefits. You can get these perks if you manage your account on their website. You may also get them when you add other services with the same supplier.

• Octopus: You can get £50 cashback when you join Octopus using a friend’s referral link.
• OVO: You get one year of free boiler cover, but be sure to read the terms and conditions.
• Utility Warehouse: You will get discounts if you get both broadband and energy together in a bundle.
• Sainsbury’s Energy: You will earn Nectar points every time you pay for energy.

These benefits will not drop your kWh rate, but they can help you save money as time goes on.

Check if you're paying too much.

Compare your current tariff with the cheapest energy deals available in your area – it only takes a few minutes.

Compare cheapest tariffs

How to Find the Best Deal for You

To find your cheapest option, consider:

• Look at your current energy usage.
• Check your meter type. It can be a smart meter, prepay, or a traditional one.
• Think about your payment method. A direct debit is often the cheapest way.
• Decide if you want a fixed tariff or if you prefer to have more flexibility.
• See if green energy is important for you or if you like to get extra perks.

It will just take a few minutes to check energy prices. You can start to switch to a better deal fast. You only need a few things to get going.

• Your email
• Your postcode
• A recent electricity bill or an estimate of your usage

FAQs About the Cheapest Energy Supplier in the UK