How to switch energy supplier

There is an increasing choice of fixed energy deals on the market, many of which could save you money. 

If you are considering a fixed tariff, compare its unit rates to what you would be paying if you stuck with the price-capped variable option you're currently on. There are currently several deals that would save you money in the long term.

Other reasons to switch could be, for example, if you are moving house, if your current supplier has poor customer service, or if you want a specialist tariff such as an EV tariff.

If you don't fix an energy deal, you will typically pay a provider's default, variable rate, which is determined by the energy price cap and changes every three months. 

Head to our guide to how to get the best energy deal, and our table of the latest cheapest deals available. 

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Can I switch energy supplier?

If you pay your energy company directly for your gas and electricity, then you can choose which supplier you use, and switch as often as you like. This will apply to most home owners. 

If you rent your home, your ability to switch supplier depends on who pays the bills. See more on how to switch energy provider as a tenant below.

When can't you switch energy supplier?

If you're on a fixed energy tariff, which means that your rate stays the same for an agreed term (usually 12 to 24 months), you may be charged an exit fee if you switch before the end of your contract. You can find out your contract end date in your online account or on your latest statement. You can switch before the end of your contract if you want, but with some exit fees reaching as much as £100 per fuel type, you'll need to weigh up the benefits of switching vs the cost of doing so. 

There are some restrictions on switching if your account with your energy supplier is in debt. You can still switch energy supplier if you're in debt, if:

• you pay by direct debit or when you receive a bill and you have owed your supplier money for less than 28 days (your debt will be added onto your final bill)
• you pay by topping up a prepayment meter and you have less than £500 debt for each of your meters (you'll have to repay this debt to your new supplier instead).

Before you switch, find out which suppliers impressed in our latest assessments of the best energy companies.

What you need to switch energy supplier

The more detailed the information you give when you're getting a quote for a new gas and electricity tariff, the more accurate it will be. Have the following handy:

1. Your full address

Prices vary by region, and some energy deals are only available in certain areas, so using your full address will make sure the quotes you get are applicable to your home. 

2. The name of your current gas and electricity supplier(s) and tariff(s)

This means that any savings estimates are compared with your current tariff. 

Otherwise, your savings may be based on a 'default', such as the company that historically supplied your area. There's a risk that this could make your estimated savings look bigger than they really are. 

Find out the name of your energy tariff on your latest bill or your online account.

3. How much gas and electricity you use

To get an accurate quote for gas and electricity costs, provide your energy use, usually in kilowatt hours (kWh), for the past year.

Your latest bill or statement should tell you how much you've used in the past month. Your annual energy statement or a summary on your online account should tell you your use over a year.

For a precise measure of how much energy you've used in a year, try this:

• find a meter reading on a past statement or your online account taken from around a year ago (an actual or smart meter reading, not an estimate)
• deduct that from today's reading. 

Electricity meters measure in kWh but most gas meters measure in cubic metres of gas. You'll need to convert this number to kWh to get a figure you can use. This calculation will be shown on your gas bill.

If you don’t know how much energy you will use – perhaps if you've just moved into a new home – you can estimate it. Price comparison websites, energy firms and auto-switching services will often ask a few questions to estimate what you use, such as:

• the number of people living in your home
• the type of property
• the number of bedrooms.

Calculating your payments in this way will be less accurate than using your actual energy use, of course. A few months into your contract, your payments could change to reflect how much gas and electricity you're using in practice.

Find out more about how to estimate your energy use.

4. Your payment details

To pay by direct debit, you'll need to provide your bank details up front. Sometimes, credit card details are permitted too.

Compare gas and electricity prices

There are several options to compare energy prices:

• Price comparison websites show you a range of deals so you can compare costs. The free and independent Which? energy comparison service is one of these. It shows all available energy deals on the market, regardless of whether we can help you switch to them, so you’ll know if the deal you pick really is the best value for you.
• Going directly to an energy company will show you its own tariffs only. It'll involve more legwork if you want to compare several companies' offerings in this way. And you won't be able to switch to any tariffs that are exclusive arrangements with third parties (such as price comparison websites). 
• Auto-switching services also compare prices based on your preferences. With your permission, they can switch you automatically to what they calculate to be the best deal for you, then keep checking prices to keep you on the best deal.

If you're on a fixed rate tariff and your contract is ending soon, your supplier will contact you to let you know your end date and details of the default tariff you'll be transferred onto if you do nothing. 

Remember that if you do nothing when your contract expires, you'll usually be switched to your provider's default, variable tariff. This is dictated by the energy price cap and your rates will change with the cap every three months.  Many suppliers offer tariffs significantly cheaper than the current price cap.   

Find out more about how to get the best energy deal

Types of energy tariff

However you compare prices, there are various types of tariff to choose from. The best tariff for you will depend on your circumstances and priorities. 

Fixed vs variable tariffs

All tariffs fall into one of two categories: fixed or variable. 

• Fixed tariffs: The prices per unit of gas or electricity, and for your daily standing charge, are fixed for the length of your deal. Fixed tariff contracts usually last between 12 and 24 months. 
• Variable tariffs: The amount you pay per unit of gas and electricity will change whenever your energy company raises or lowers its prices. This is usually in line with three-monthly changes to the Ofgem's energy price cap, though suppliers are free to change them at any time. Your supplier must give you 30 days’ notice if the change will make you worse off.

Time-of-use tariffs

Most tariffs charge the same rate no matter what time of day you use energy. However there are a few time-of-use tariffs which charge different amounts depending on when you use electricity. Time-of-use tariffs can be fixed or variable. 

• Smart time-of-use tariffs use half-hourly smart meter readings to allow companies to charge lower rates when demand is lower and electricity is cheaper. 
• Economy 7 and Economy 10 give seven or 10 hours of cheaper electricity, mostly overnight. They're becoming less common as smart meters are becoming more widespread.

Other terms you may encounter

• Dual-fuel tariff: an energy tariff including both gas and electricity. They're handy for reducing your admin.
• Paperless or online-only tariff: you won’t get bills through the post, and will need to manage at least some of your account online. Some suppliers charge less for these, but not all.
• Tracker tariff: The amount you pay will change every three months when the price cap is reset. Most providers guarantee a discount on the price cap, regardless of how it changes.
• EV tariff: this is a variant on a time--of-use tariff that offers cheaper rates to charge your electric vehicle (EV) at lower-demand times of day. 

Find out more in our guide: energy tariffs explained

Energy tariffs: what to check before you switch

If you're considering switching energy tariff, check the following:

• Does your tariff have exit fees? We've seen exit fees of £100 per fuel if you want to leave before the end of your contract. Exit fees only apply to fixed-term deals (including some tracker tariffs), and cannot be charged in the last 49 days of your tariff.
• How much will your new deal cost per month? Check how this compares with your current payments.
• Is your direct debit fixed or variable? Fixed direct debit payments are the same each month, to balance out the cost of your energy during the year. Variable direct debit payments change each month to match what you use.
• How will you receive your bills? Some tariffs are online-billing only - you won't get a paper bill through the post. 
• Does your tariff require a smart meter? Some tariffs are only available to customers with smart meters, or if you agree to have one fitted.
• Is there an upfront payment? Some tariffs require one month's payment (or even two, in some cases) before they start supplying your gas and electricity. Some prepayment deals require a security deposit. 
• Will the supplier deal well with any issues? Our annual analysis of the best energy suppliers can help you choose a provider that treats its customers well. 

Find out more: How to choose the best energy supplier

Do I need to tell my current energy supplier that I'm switching?

No, you don't need to contact the energy company you're leaving. 

Your new supplier will set up your switch and tell your old supplier. 

It's worth sending both suppliers a meter reading on the day you switch to make sure that both bill you correctly. You shouldn't need to do this if you have a smart meter sending daily (or more frequent) meter readings.

If you're moving home, tell your energy supplier at least 48 hours in advance (ideally more). Some may let you start the process around a month in advance. You might be able to take your existing tariff with you.

If not, contact the supplier at your new property to tell them that you've moved in. You can find out the energy supplier for your property on the Ofgem website if the previous occupant hasn't left details.

Use our moving house checklist to find out who else you need to contact when moving home.

How long does it take to switch energy supplier?

Energy suppliers have five working days to move you from your old energy supplier to your new one. That's according to rules in place since 1 April 2024.

If they don't meet the deadline, you're owed £40 compensation from your new supplier.

This five-day deadline is separate from 14-day cooling-off period the supplier must allow from the day after you agree to the new contract, in case you want to change your mind before it begins the switch.

Previously energy suppliers had 15 working days to complete your switch while only those signed up to the Energy Switch Guarantee aimed to complete your switch within five days.

Energy Switch Guarantee signatories are: British Gas, Ecotricity, EDF Energy, E.On Next, Fuse Energy, Octopus Energy, Outfox Energy, Ovo Energy, Scottish Power and So Energy (correct November 2025).

Find out more about the Energy Switch Guarantee.

Will I get compensation if I have a problem switching?

If something goes wrong when you switch energy supplier, you may be eligible for compensation.

Energy firms must pay customers £40 if: 

• you are switched without your permission or by mistake
• your switch is not completed within five working days (after the 14-day cooling-off period has elapsed)

You can get an extra £40 if: 

• your supplier fails to send you the compensation you are entitled to within 10 working days
• your supplier takes more than 20 working days to reply to you after you tell them about a switching mistake
• your old and new suppliers take more than 20 working days to decide whether the switch was correct (you get £40 from each)
• your supplier takes more than 21 working days to re-register your supply after finding out about the mistake.

These rules are set by Ofgem. If a supplier goes out of business, then different rules apply. 

The compensation is automatic, although you may need to tell your energy supplier about the problem. 

How to switch energy supplier as a tenant

If you rent your home and pay your energy company directly for your gas and electricity, then you can choose your energy supplier according to consumer protection law. You should inform your landlord or letting agent, though, and there may be a clause in your rental agreement that requires this.

But if your landlord pays the energy company themselves, they will choose the energy supplier. You might be in this situation if:

• your energy costs are included in your rent
• your landlord pays your energy supplier and reclaims the money from you
• your landlord has taken responsibility for energy bills between tenancies.

Your tenancy agreement should state whether you or your landlord is responsible for paying the gas and electricity bills. If your landlord pays the energy bills, you can ask them to change your supplier, but they don’t have to.

Your tenancy agreement might include a ‘default’ or preferred energy supplier that your landlord or estate agent has set up to supply your energy when you first move in. There may also be a clause stating that you must return the account to the original energy supplier when you move out. You can ask to renegotiate these clauses in your contract. 

If you've just begun a new tenancy, or haven’t switched energy supplier or tariff in a while, it’s likely you’re on the energy firm’s standard default or out-of-contract tariff. 

If you have a prepayment meter and rent your home, you should still be able to switch. Find out more about prepayment energy meters.