How to Change Energy Supplier: A Complete Guide

Introduction to switching energy suppliers

Changing your energy supplier is entirely an administrative process. Your new supplier uses the exact same pipes, wires, and meters to deliver gas and electricity to your home. Nobody needs to visit your property, and your power will not be cut off during the changeover.

Many households stick with the same energy provider for years because they worry that moving will be complicated or cause disruption. In reality, the systems that manage energy switches in Great Britain have been upgraded to make the process fast and reliable. Whether you want to cut your monthly bills, find better customer service, or move to a tariff that uses zero-carbon electricity, changing supplier is straightforward.

Why switch energy supplier right now?

The energy market shifts constantly, and the price you pay depends heavily on the Ofgem price cap. This cap limits the maximum amount a supplier can charge for each unit of gas and electricity, as well as the daily standing charge. It does not cap your total bill — if you use more energy, you will pay more.

Following a sharp increase in wholesale gas costs, the price cap rose by 13% in July. For a typical household paying by Direct Debit in Great Britain, the cap is currently set at £1,663 a year. Industry analysts forecast that prices will rise again in October, meaning households on standard variable tariffs will see their bills go up just as the colder weather sets in.^[1]

Because of these forecast increases, switching to a competitive fixed tariff can protect you from future price hikes. Depending on how much energy you use and where you live, locking in a fixed deal now could save you between £90 and £250 a year compared to staying on a standard variable rate.

Understanding your tariff options

Before you change supplier, it helps to understand the two main types of energy tariff available. The type of tariff you choose affects how much you pay, whether your prices can change, and whether you will be charged a fee if you leave early.

A standard variable tariff (SVT) goes up and down in line with the Ofgem price cap. If the cap rises, your unit rates and standing charges rise. These tariffs offer flexibility because they never come with exit fees, meaning you can leave at any time without penalty. If you have never switched supplier, or if your previous fixed deal ended and you did not choose a new one, you will be on a standard variable tariff.

A fixed tariff locks in your unit rates and standing charges for a set period, usually 12 or 24 months. If the price cap goes up, your rates stay exactly the same. However, fixed tariffs usually carry an exit fee if you decide to leave the contract early. These fees vary by supplier and the length of the fix. For example, British Gas currently offers a 14-month fixed tariff with a £100 exit fee per fuel, and a 24-month fixed tariff with a £150 exit fee per fuel. You must weigh the security of fixed prices against the cost of leaving early.

Rates can differ by payment method, so compare the tariff available for your meter and how you pay. While paying by monthly Direct Debit is common, suppliers also offer rates for paying on receipt of your bill or using a prepayment meter.

How to switch energy supplier: step by step

The actual process of changing provider is simple and requires very little effort on your part. You just need a recent energy bill to hand.

How long does the switch take?

In the past, switching energy suppliers could take up to three weeks. Today, a switch requested as soon as possible should be completed within five working days. If you ask for it to begin after the cooling-off period, it will take longer overall.^[1]

By law, you are entitled to a 14-day cooling-off period when you sign up for a new energy tariff. It starts the day after you agree the contract. You can choose an immediate switch, which can complete during this period, or ask for the switch to begin after it ends.

If you choose an immediate switch, it can complete during the cooling-off period. You can still cancel the new contract within 14 days, but contact your new supplier promptly to confirm how it will handle your supply and billing.

What happens to your credit or debt?

Many people worry about losing the money built up in their energy account, or think they cannot switch because they owe their supplier money. The rules around credit and debt are clear and designed to protect consumers.

If your account is in credit when you switch, your old supplier must refund that money to you. Under Ofgem's Guaranteed Standards of Performance, your old supplier has exactly six weeks to issue your final bill. Once that bill is issued, they have 10 working days to refund any remaining credit balance to your bank account. If they miss either of these strict deadlines, they must automatically pay you £40 in compensation.

If you owe money to your supplier, you may still be able to switch depending on your meter type. If you use a prepayment meter, the Debt Assignment Protocol allows you to switch suppliers with up to £500 of debt per fuel (so £500 for gas and £500 for electricity). The debt simply transfers to your new supplier, and you continue paying it off through your meter exactly as before.

If you have a standard credit meter and pay by Direct Debit or on receipt of a bill, you cannot switch if you have debt that has been outstanding for more than 28 days. You will need to pay the debt off before your old supplier will allow the switch to go ahead. If the debt is less than 28 days old, the switch will proceed, and the amount you owe will be added to your final bill.

The seasonal credit trap

When you pay by fixed monthly Direct Debit, you build up credit during the summer when you use less heating, and use that credit to cover higher bills during the winter. This smooths out your costs so you pay the same amount every month.

If you switch supplier in the summer or early autumn, your old supplier will refund the credit you have built up. This feels like a windfall, but it means you start your new account with a £0 balance just as the high-usage winter months arrive.

Because your new supplier needs to cover your expensive winter energy use without the benefit of a summer credit buffer, they may set your initial Direct Debit much higher than you expect. To manage this, it is wise to keep the credit refund from your old supplier in your bank account, rather than spending it, so you can use it to cover any higher payments during the winter.

Renters, smart meters, and government schemes

If you rent your home, your right to switch depends on who pays the bill. If your name is on the energy account and you pay the supplier directly, Ofgem rules state that you have the right to choose your supplier. A landlord or letting agent cannot force you to stay with a specific company. However, if your landlord pays the energy bill and then charges you for it, you cannot switch the supplier yourself.

Households that receive the Warm Home Discount need to take extra care when switching. This government scheme currently offers a £150 rebate on winter electricity bills. If you are eligible under the Core Group, the supplier you were with on the scheme’s qualifying date should arrange payment, even if you subsequently switch. In Scotland’s Broader Group, check whether the new supplier participates and whether you meet its criteria; if you have already been approved, wait until you receive the rebate before switching.^[1]

Should you switch energy supplier?