We use cookies to allow us and selected partners to improve your experience and our advertising. By continuing to browse you consent to our use of cookies as per our policy which also explains how to change your preferences.

How to save on your energy bill

How to switch energy supplier

Article 3 of 5

Put us to the test

Our Test Labs compare features and prices on a range of products. Try Which? to unlock our reviews. You'll instantly be able to compare our test scores, so you can make sure you don't get stuck with a Don't Buy.

How to switch energy supplier

Switching energy supplier could save you hundreds of pounds on your gas and electricity bill. So what are you waiting for? Find out how to switch.

Make sure you're not paying more than you should for gas and electricity. Use our expert advice to find out what you need to switch, and how to get the best deal for you.

Switching to a cheaper energy deal is a quick and easy way to save money. In fact, you could save yourself hundreds of pounds. 

Here, we tell you what information you need to switch, plus explain the different types of tariff available. 

What you'll need to switch

The more information you can provide to an energy comparison website, the more accurate your quote will be. Make sure you have this information to hand:

  • Your postcode
  • The name of your current gas and electricity supplier, and the name of your tariff. If you're not sure, look at your latest bill or contact your supplier
  • How much you use in kilowatt hours (kWh) on gas and electricity, or how much you spend. Again, look at recent bills - or even better, look at your annual energy statement
  • Your bank or credit card details if you decide to switch and want to pay by direct debit.

The best way to find the cheapest energy deals is by visiting an independent energy comparison website, such as our own Which? Switch. Use Which? Switch to compare gas and electricity prices

How long does it take to switch energy supplier?

It takes 16 days to switch your electricity supplier and 17 days to switch your gas supplier, on average, according to energy regulator Ofgem*.

That’s not including the 14 days cooling-off period the supplier must leave in case you want to change your mind before they begin the switch.

When we spoke to energy customers who had found switching energy supplier difficult** in September 2017, the most common reason (cited by 24% of frustrated switchers) was that the process was too slow.

For a quicker switch, choose a company signed up to the Energy Switch Guarantee.

So if you’re keen for a quicker switch, choose a company signed up to the Energy Switch Guarantee. These companies guarantee to switch your energy supply within 21 days (including the cooling-off period).

Companies signed up are: British Gas, EDF Energy, Eon, Npower, Scottish Power and SSE.

Plus Bulb, Ecotricity, Energy SW, Enstroga, Fairer Power, First Utility, Flow Energy, M&S Energy, Octopus Energy, Ovo Energy, Peterborough Energy, Pure Planet, Sainsbury’s Energy, So Energy, Southend Energy, Spark Energy, Tonik Energy and Utility Warehouse (correct June 2018).

They also guarantee to contact your old energy supplier to tell it you’re leaving, work with it to make sure you’re not charged twice, and take responsibility if there are any problems. 

Once you have switched, they promise to send you a final bill within six weeks, and refund you any money owed within. Find out more about the Energy Switch Guarantee.

*(As stated December 2017.)

**(Survey: September 2017, 8,397 energy customers.)

Types of energy tariff

There are a huge number of tariffs and deals on the market - here's a quick introduction to what's available:

Dual-fuel tariffs

If you want to get your gas and electricity from the same supplier, then taking a dual-fuel deal will pretty much always work out cheaper because of the dual-fuel discount. 

However, this isn’t the case with every supplier. Eon scrapped its dual-fuel discount in April 2018.

But if you are prepared to have separate suppliers for your gas and your electricity, then seeking out the absolute cheapest deals for each fuel could save you even more.

Compare and switch suppliers

Choose the fuel type
to compare:

Gas and electricity Electricity
only
Gas only

Online energy tariffs

If you choose an online (or paperless) tariff, you won't receive bills through the post and you'll have to manage at least some of your account over the internet. 

Many companies offer a discount for managing your account this way, and you can still call customer services if you have a problem and would like to speak to someone. 

But check carefully; both Eon and SSE scrapped their paperless billing discounts in 2018.

Fixed-price energy tariffs

Fixed-price tariffs guarantee the price you pay for each unit of energy you use for a set period of time, and may give peace of mind if you're worried about possible future price rises. 

Fixed deals tend to be cheaper than standard (variable) tariffs. The cheapest tariffs of the biggest 10 energy suppliers, mainly fixed deals, were between £78 and £218 cheaper than their standard variable tariffs in March 2018.

Some fixed deals come with exit fees. We’ve seen these range from £5 to £50 per fuel, payable if you choose to cancel the tariff before the end of the period (usually one, two or three years). Check with the supplier before you sign up.

Standard tariffs

It is estimated that around two thirds (66%) of households are on a standard tariff for their energy. 

A standard tariff (also known as a ‘variable’ tariff) is usually your supplier’s default tariff. If you have been with your supplier for a while or didn’t switch after your fixed deal came to an end, it is very likely you are on it. The cost of standard tariffs will go up and down each time your supplier changes its rates. 

Our analysis of energy tariffs has found that customers of the Big Six energy companies who are on a standard tariff could save more than £300 in a year by switching to the cheapest deal on the market. So if you’re on a standard tariff and you want to save money, it's time to switch. 

However, some new small energy firms offer variable tariffs which are much cheaper than the large suppliers. They too can change their rates but are still worth considering if you’re looking to pay less without the tie-in of a fixed contract.

Use our independent switching site, Which? Switch, to find the cheapest energy deal.

Off-peak electricity tariffs

Off-peak electricity tariffs, such as Economy 7 and Economy 10, are best suited to people who can use more than 60% of their electricity late at night, such as those who heat their homes using storage heaters

Economy 7 and 10 users have a special meter that can keep track of electricity units charged at different unit rates – a higher rate in the daytime and a lower rate between certain times at night or in the afternoon.

Smart meters bring the potential for more time-of-use tariffs, for example those geared around when you use energy. Few companies are offering these so far but they are expected to become more popular as smart meters are rolled out.

Considering getting a smart meter: here’s what you need to know about smart meters.

Social tariffs

Social tariffs have traditionally been available to vulnerable customers struggling to pay their bills. These have now been replaced by a payment scheme called the Warm Home Discount. To find out more, and to see whether you're eligible, go to Warm Home Discount

See our advice if you need help paying bills.

There is also a price cap in place for customers who receive the Warm Home Discount or who pay for energy using a top-up meter. 

Energy jargon buster

Kilowatt hour (kWh)

A unit of energy used on energy bills, showing how much power is used over a period of time. If an appliance uses 1,000 watts each hour and you run it for an hour, you have used 1kWh.

Standing charge

A standing charge is a fixed charge that you pay, often daily, regardless of whether or not you have used any energy. For very low users or second properties, it is worth seeking a tariff with a low or zero standing charge.

Unit rate

How much you are paying for each unit of energy that you use (on top of the standing charge).

Membership fee

Some newer energy companies, including Outfox the Market and Pure Planet, charge a membership fee. Like a standing charge, this covers the fixed costs of supplying your energy. On top of this you pay for the units of electricity and gas used.

Find out how much money you can save by switching your energy tariff. Use Which? Switch to compare gas and electric

SHARE THIS PAGE