Compare energy deals: how to find the cheapest for your home

Written by: EnergySwitch editorial team · Last reviewed: 3 November 2026

Short answer: To find the cheapest energy deal for your home, compare tariffs on your own annual kWh, not a typical bill. Add up unit rates and daily standing charges for a full year, then add any exit fee for leaving your current deal early. Check more than one comparison service, because not every site shows every tariff.

How energy comparison sites work

Most comparison sites are free to use. They are usually paid a commission by a supplier or partner when you switch through them. That is how they fund the service.

They may not show the whole market. Ofgem’s rules for comparison sites changed in 2018. Sites accredited under its voluntary Confidence Code may choose to show only deals you can switch to directly through them, if they meet conditions set by Ofgem. Under the code, an accredited site must not say or imply that it shows every tariff unless that is true. Citizens Advice says not all websites show the same tariffs and suppliers, so it is worth checking a few. Some tariffs are only available direct from the supplier.

Accreditation. Ofgem runs the Confidence Code, a voluntary code of practice for domestic energy comparison services. The code’s published requirements cover independence, how results are ordered, commission disclosure and market coverage. If accreditation matters to you, check what a site says about its own status and confirm it with Ofgem. EnergySwitch does not claim Confidence Code accreditation.

What to check on any comparison site:

• Does it say whether results cover the whole market or only some suppliers?
• Are results shown with VAT, unit rates, standing charges and exit fees?
• Does it explain how it is paid?
• Can you enter your real kWh rather than a house size?

Reading a quote: unit rate, standing charge, total

Every quote has two prices for each fuel:

• Unit rate: pence per kWh you use.
• Standing charge: pence per day, whether you use energy or not.

Annual cost = (kWh × unit rate) + (standing charge × 365), for each fuel.

Worked example: the price cap as a baseline. These are Ofgem’s average Direct Debit capped rates for 1 October – 31 December 2026, applied to Ofgem’s typical usage of 2,500 kWh of electricity and 9,500 kWh of gas. They are a baseline, not a quote.

Together that is about £1,723, Ofgem’s typical figure. Now put a quote’s rates into the same table with your kWh. If its total is lower, it is cheaper for you on today’s rates. Capped rates change every three months; a fixed deal does not.

Two things this shows:

• Standing charges matter more for low users. In the example, the electricity standing charge is about £200 of £858. If you use less, that share grows, so a tariff with a lower standing charge may win even with a higher unit rate.
• Headline “cheapest” depends on usage. The cheapest tariff for a typical home may not be the cheapest for a flat with low use or a home with an EV or heat pump.

Our fix vs price cap calculator does the sum for you. For current rates by region, see the energy price cap hub.

Exit fees: when paying one still saves money

An exit fee is a charge for leaving a fixed tariff before it ends. Citizens Advice says you might save more by switching, even if you have to pay an exit fee.

The test: saving over the rest of your current term − exit fee = what you gain.

1. Work out what you would pay on your current rates for the months left on your fix.
2. Work out what you would pay on the new deal for the same months.
3. Take away the exit fee (check whether it is per fuel).

Illustration only, not a real tariff: if the new deal would cost £80 less over your remaining months and the exit fee is £30 per fuel (£60 for dual fuel), you would be about £20 better off. If the exit fee were £50 per fuel, you would be £20 worse off.

Free switching window. Ofgem’s licence rules say suppliers should not charge exit fees for a switch within the 49-day switching window before a fixed term ends. If you are close to the end, waiting until you are inside the 49 days may cost nothing. Ask the new supplier for a switch date.

Remember the new deal may have its own exit fee. If you might move home or want to leave if prices fall, a lower exit fee keeps your options open. For the fix-or-cap decision, read should I fix my energy before January 2027?

Dual fuel, single fuel and green tariffs

• Dual fuel: gas and electricity from one supplier. Simpler, but compare the total against two separate single-fuel deals.
• Single fuel: one fuel from each supplier, or electricity only if you have no gas. Each has its own standing charge.
• Green tariffs: check what the supplier says backs the tariff, and compare the price like any other deal.

How we make money

Using EnergySwitch is free. If you click a comparison link on this site and switch, we may earn a commission from a comparison partner or supplier. The business you deal with pays it, and it is not added to your energy bill. A comparison service can only show and switch you to the tariffs it has access to, so it may not cover every deal on the market. You can also check other comparison services or switch direct with a supplier. Read more about EnergySwitch and our terms of use.

When you are ready, follow how to switch energy supplier, or start at compare gas and electricity.

FAQs

Do energy comparison sites show every tariff?

Not always. Many show only deals from suppliers they work with, or only deals you can switch to through them, and some tariffs are only available direct from the supplier. Citizens Advice suggests checking a few sites. Look for a clear statement of whether a site covers the whole market.

Is it worth paying an exit fee to switch energy?

It can be, if what you save over the rest of your fixed term is more than the exit fee. Work it out with your own usage before switching. If you have 49 days or less left on your fix, Ofgem’s rules say you should not be charged an exit fee at all.

How do energy comparison sites make money?

Usually through commission. A supplier or partner pays the site when you switch through it. The service is free to you, and the commission is not added to your bill. Under Ofgem’s voluntary Confidence Code, accredited sites must disclose which suppliers pay them commission.

How do I compare energy deals properly?

Use your annual kWh from a recent bill or your supplier’s app. For each tariff, multiply your kWh by the unit rate, add the standing charge times 365, and do this for each fuel. Add any exit fee. The lowest total for your usage is the cheapest deal for you.

Is the cheapest energy deal always the best?

Not always. Check the exit fee, the length of any fix, the payment method required and the supplier’s customer service. Citizens Advice publishes customer service ratings for the largest suppliers. A slightly dearer deal with no exit fee may suit you if you expect to move.

Are dual fuel deals cheaper than separate suppliers?

Sometimes, but not automatically. Compare a dual fuel quote with the best single-fuel electricity and gas deals added together, using your own usage. Each separate account has its own standing charge, so include both in the total.

Sources

All accessed 3 November 2026.

• Ofgem: Confidence Code, code of practice for online domestic price comparison services (2017) (requirements; no “whole of market” wording unless true)
• Ofgem: Decision letter on the Confidence Code whole-of-market requirement (16 July 2018) (sites may show only switchable deals)
• Ofgem: Switch your home energy supplier (compare via suppliers or comparison sites; exit fees)
• Ofgem: Licence guide, switching (49-day switching window)
• Citizens Advice: Switch energy supplier or tariff (check several sites; exit fee may still be worth paying)
• Ofgem: Energy price cap unit rates and standing charges (baseline rates; £1,723)

Disclosure: EnergySwitch may earn a commission if you switch through some links on this page. It does not change the price you pay.