How to Switch Energy Supplier: A Step-by-Step Guide

Last reviewed: 12 October 2026

Whether you are buying a new home, moving homes, renting a new place, simply want to save money or get new perks, switching energy supplier is a good place to start. Switching your energy supplier is free, does not interrupt your gas and electricity and should not take more than five working days.  

This guide walks through the whole journey: preparing to switch, what happens during the process, what to expect with meter readings and your final bill, your right to change your mind, and what to do if something goes wrong.

Before you switch

A few things are worth checking first:

• Your current contract and any exit fees. If you are on a fixed-rate deal, switching before it ends may mean paying an exit fee. Check your current terms before comparing new deals.
• Your current supplier, tariff name and unit rates. You will need these to compare accurately and to give your new supplier when you sign up. They are shown on your latest bill.
• Your annual energy usage in kWh. Your energy usage figure can be found on your bill and is helpful for comparison. 
• Whether you owe your current supplier money. This affects whether you can switch straight away, covered in more detail below.
• Your postcode. Needed to check which tariffs and suppliers are available at your address.

Having your latest bill nearby can make this much easier, as most of the information you need will be listed there. If you are unsure about anything on your bill, our energy bills explained guide can help you understand what the different charges and figures mean.

How the switching process works

Once you have chosen a new supplier and tariff, you give them the details above, and they take it from there. Ofgem confirms that your new supplier contacts your old one and manages the process, and it should take up to five working days from when you sign up to when the switch completes. You can also ask to schedule it on a later date if you would prefer.

Your gas and electricity supply is not interrupted during a switch, since you are changing your supplier and not the physical pipes or wires that supply your home.

If your new supplier does not complete the switch within five working days, you are entitled to compensation. If you are considering a particular supplier, our guides to British Gas, E.ON Next and So Energy explain more about their tariffs, services and what to consider before signing up.

Comparing tariffs before you switch

Ofgem maintains a list of accredited energy comparison services that follow its Confidence Code. The code sets standards around transparency, accuracy and how tariffs are presented. 

When comparing, it is worth looking beyond the headline unit rate to the standing charge, contract length, and any exit fees, since the cheapest-looking rate is not always the cheapest overall deal for your usage.

Unit rates: 

This is the amount you pay for each unit of gas or electricity you use, measured in kWh. A lower unit rate can reduce your bills if your household uses a lot of energy. A change in energy price cap may affect your unit rates.  

Standing charge: 

This is a fixed daily charge you pay regardless of how much energy you use. A tariff with a lower unit rate but a higher standing charge may not work out cheaper overall.

Estimated annual cost: 

Comparison services use your expected annual usage to estimate what you could pay over a year. Using your actual kWh usage from a recent bill will usually give you a more useful comparison than relying on generic household estimates.

Fixed or variable tariff: 

A fixed tariff locks in the unit rates and standing charge for a set period, while a variable tariff can change according to its terms. Check how long a fixed deal lasts and what happens when it ends.

Standard tariff: 

If you are not on a fixed deal, you may be on your supplier's standard variable tariff. Its rates can change, so compare it with other available options rather than assuming it is your cheapest choice. 

Exit fees: 

Some fixed tariffs charge a fee if you leave before the end of the contract. Check the amount before switching, particularly if you think you may want to move again soon.

Payment method: 

Some tariffs have different rates depending on how you pay, such as by Direct Debit or another payment method. Make sure the quoted price reflects how you actually intend to pay.

Renewable energy or other features: 

If this matters to you, check what the tariff actually includes rather than choosing based on the supplier or tariff name alone.

Dual fuel tariffs: 

If you need both gas and electricity, you may be able to get both from the same supplier. Compare the overall cost of a dual-fuel deal with separate gas and electricity tariffs to see which works out better for you.

Additional terms: 

Look for any conditions attached to the deal, including eligibility requirements, discounts, rewards or other features that could affect the overall value. Check out Energy supplier offering rewards for current perks. 

The cheapest-looking tariff is not necessarily the cheapest option for everyone. Your annual energy usage, payment method and the terms of the deal can all affect what you actually pay. 

Once you know what to look for, compare your options to see whether another tariff could suit your household better. An automatic switching service also helps to stay on top of your energy bills and switch hassle free. 

What happens to meter readings and your final bill

Submitting an accurate meter reading on the day your new supply starts helps make sure your opening and final bills are correct rather than estimated. If you have a smart meter, readings are usually sent automatically, so there is often nothing extra to do. If you are unsure how to take a meter reading, our guide to reading your meter walks you through the process.

Your previous supplier is responsible for sending your final bill. If you have used more than you have paid for, you will owe the difference. If you are in credit, your old supplier has to refund what you are owed for energy you did not use. If your account is in credit, our guide on what to do if your energy supplier owes you money explains what you can do next.  

The cooling-off period

New domestic energy contracts can be cancelled within 14 days if you change your mind, free of charge. This is called the cooling off period.

This is a statutory right that applies to new domestic energy contracts. Most business energy contracts do not carry the same right, so this mainly applies to household switches.

Switching if you are in debt to your supplier

Whether you can switch depends on how long the debt has been outstanding and when it was billed:

• Debt that has been billed for less than 28 days: you can switch as normal. Your old supplier adds what you owe to your final bill.
• Debt that has been billed for 28 days or more: you cannot switch if your supplier has sent a bill more than 28 days ago which has not been paid. 
• Prepayment meters: you can still switch if you owe less than £500 per fuel to your current supplier.

We explain this in detail in our guide on switching suppliers if you are in debt. If you are struggling to keep up with your energy payments, you may be able to get help with the underlying bill before focusing on switching. Our guide to dealing with a high energy bill covers the practical steps you can take.

Switching if you are moving home

Moving home is slightly different from switching supplier at your current address. You need to tell your existing supplier that you are moving out, while the new property will normally already have an energy supplier. Once you move in, you can choose to stay with that supplier or switch to another one. 

Before leaving your old property, give your supplier your moving-out date and take a final meter reading. At your new property, take another reading when you move in and give it to the existing supplier. This helps make sure you are only charged for the energy you use. 

If you are responsible for the energy bills at your new home, you can switch supplier and tariff once you have moved in. If you are renting, check your tenancy agreement first, as it may contain information about which suppliers you can use or whether you need to notify your landlord or letting agent. 

For a full explanation of what to do before, during and after your move, see our guide to switching energy bills when you move house.

If something goes wrong

• If your switch is delayed beyond five working days, your new supplier must pay you £40 compensation automatically, without you needing to claim it. Ofgem's current rules set this at £40, paid directly into your energy account or bank account.
• If you are switched without agreeing to it (sometimes called an "erroneous transfer," for example if a supplier mixes up your address with someone else's, or you were misled by a salesperson), contact your old supplier to let them know. Your new supplier must pay you £40 compensation automatically for an erroneous transfer.
• If compensation itself is paid late, or a supplier is slow to resolve a switching mistake, further compensation can apply under Ofgem's Supplier Guaranteed Standard of Performance.
• If you are unhappy with how a switch was handled, your supplier's complaints process is the first step; if that does not resolve things, you can escalate to the Energy Ombudsman.

Many suppliers also participate in the voluntary Energy Switch Guarantee, which sets out additional commitments around communication and timing during a switch. Our Energy Switch Guarantee guide explains how these commitments work and how they differ from the statutory rights covered on this page.

Frequently asked questions