How to Switch Energy Supplier: The Steps From Quote to Final Bill

Switching energy supplier changes who you pay, not the energy itself. The gas and electricity arriving at your home are exactly the same, the pipes and cables are unchanged, and both supplies should continue without interruption on the day of the switch¹. What changes is the company that bills you, the tariff you are billed on, and the price per unit and daily standing charge you pay.

The process is faster than many people expect. Suppliers must complete a switch of your electricity or gas supply within five working days, a standard in force since 1 April 2024³. Your old supplier then sends a final bill, which should arrive within six weeks, and refunds any credit on your account². If you pay a supplier directly for the energy you use at home, you can choose to switch to a different supplier or tariff at any time³.

What changes when you switch, and what stays the same

A switch moves your account from one supplier to another. It does not move your meter, your pipes or your cables, and it does not interrupt your supply: both gas and electricity should be unaffected on the day the change happens¹. The energy you receive is the same energy; only who you pay for it changes¹.

The right to switch belongs to whoever pays the supplier directly. If you pay a supplier directly for the electricity or gas you use at home, you can choose to switch to a different supplier or tariff at any time³. There are no limits on how many times you can switch². If your home has a Green Deal loan attached to it, you can still change electricity supplier as long as the new supplier is taking part in the Green Deal scheme⁷. And if your home is supplied through a business contract, for example in some flats or sheltered housing, the position is different: you may be able to switch your business energy supplier if you have your own contract⁸.

One situation removes the choice entirely. If your supplier goes out of business, you do not need to do anything: Ofgem will automatically move you to a new supplier and make sure your energy supply is not interrupted³. You can then switch from that appointed supplier to another one if you want to, without any exit fees⁹.

For a household thinking about energy independence, it is worth being clear about what a switch delivers. It changes the price you pay and the company that answers the phone, but it does not change your dependence on the grid, on gas, or on a supplier's own pricing decisions. As the smart meter network operator puts it: "Except by switching, you don't control the tariff your energy supplier sets, but you can change how much energy you use."¹⁰

Knowing your current tariff: fixed or variable

Before comparing deals, you need to know what you are on. The two main categories are fixed tariffs, where the unit rate is locked for a set term, and standard variable tariffs, where the rate your supplier charges can change. Your latest energy bill or statement shows your current tariff, and the same information is usually in your supplier's app or online account¹¹. The bill also shows your annual energy usage or costs, which is what a comparison service needs to quote you accurately¹².

The bill itself is built from three things: the amount of energy you use, the unit cost, and the daily fee, the standing charge¹³. When you compare tariffs, the factors that matter are the unit rates and standing charges, whether prices are fixed or can change, the length of any fixed-term contract, the payment methods available, customer service and support, and any additional benefits or incentives¹¹.

How confident are people about what they are on? Less than they think. Ofgem's 2024 research on tariff choices found considerably more consumers claiming to be on fixed tariffs, 38%, than the official data suggests, 11%¹⁴. Among those who say they are on a fixed electricity tariff, 55% report being "very confident" this is the case, while 38% say they are only "somewhat" confident¹⁴. Checking the bill rather than guessing is therefore the first step of any switch.

Fixed tariffs: the parts that stay put and those that move

A fixed tariff locks in the unit cost of your energy and the daily standing charge for the length of the contract¹⁵. What it does not lock in is your bill. The amount you are charged is still set by the amount of energy you use, the unit cost and the daily fee, so a cold winter on a fixed tariff still costs more than a mild one¹⁵.

The trade-off for price certainty is commitment: on a fixed rate you are often locked into the deal for a set period¹⁶. Most fixed tariffs include exit fees for each fuel, payable if you switch before the contract ends¹⁷. Those fees can apply even when you are not leaving your supplier: Ofgem's research found only 57% of consumers could identify that exit fees may still apply to a fixed contract even when moving to another deal with the same supplier¹⁴.

If your fixed tariff has already ended, you are free: you can still switch supplier or tariff at that point, with no fee¹⁵. The lock only exists while the contract is running.

How fixed deals compare with the price cap

Fixed deals typically run for 12 months, though terms of 12 to 24 months are common². The comparison that matters is against the standard variable rate, which is determined by the energy price cap and changes every three months⁴. When a fixed rate expires, the supplier moves you to the standard variable tariff, which is typically higher than fixed rates¹⁸.

How much cheaper a fix works out depends on the market at the time and on your usage pattern, so no single figure holds. One modelled example from Ofgem's 2025 impact assessment gives a sense of scale: households that do not generally use electricity at peak times, between 4pm and 7pm, could save over £200 a year by switching from the price cap to a tariff that changes price throughout the day¹⁹. That is a flexibility tariff rather than a standard fix, but it shows the size of gap that can open between the cap and a deal shaped around how you actually use energy.

Tariffs offered by energy suppliers may include standard variable tariffs, renewable energy tariffs, electric vehicle tariffs, fixed price tariffs and prepayment tariffs²⁰. The range matters because the cheapest headline rate is not always the right shape for a household: an electric vehicle tariff, for instance, prices electricity very differently across the day.

Exit fees and the 49-day window without penalty

If you were on a fixed-rate tariff and chose to leave before it ended, you may have to pay your previous supplier an exit fee³. The rules around those fees have two important carve-outs.

The first is at the start of the contract. You cannot be charged an exit fee if you switch tariff during the 14-day cooling-off period at the start of the contract². The second is at the end: your provider cannot charge exit fees if you switch within 49 days of your current deal ending⁶. The same 49-day rule appears across independent guidance: you can switch for free in the final 49 days of the contract rather than having to wait for it to end completely¹⁷, and customers are entitled to switch to a new deal or supplier from 49 days before the end of their contract²¹.

Exit fees clearly shape behaviour. In Ofgem's research, when consumers who thought they had an exit fee on their current contract were shown a deal with a £300 exit fee, 70% said they would switch; shown a deal with no exit fee, 93% would¹⁴. The fee itself is a smaller obstacle than the belief in it.

Your fixed deal ends and rolls over without you doing anything

Nothing happens by itself except the one thing you probably do not want. When your fixed deal ends, your supplier will automatically move you onto its standard variable tariff¹³. With a fixed rate, you roll onto your provider's standard variable rate when the tariff ends⁶, and customers who do not sign a new deal are probably rolled onto that same tariff²¹. The supplier should remind you when the contract is about to end¹⁵.

The standard variable tariff is typically higher than fixed rates¹⁸, so the rollover usually means paying more without doing anything. The protection is the 49-day window described above: if you switch with 21 to 49 days left on your current tariff, you avoid spending days or weeks on the old deal's terms while still paying no exit fee².

The practical habit this suggests is a regular one. Independent guidance recommends switching as a matter of habit every 12 to 18 months, which matches the typical length of fixed deals²¹. A household that fixes, diarises the end date, and re-compares inside the final 49 days never sits on the variable rate for long.

Moving house: the tariff you take on and your first meter reading

A move changes the picture. When you move into a new home you will automatically be put onto a "deemed contract" with the existing supplier, which will be for their "default" or "standard variable" tariff²². That is the tariff you inherit, and it is usually not the cheapest thing that supplier offers.

The steps for a new home are straightforward: find out who your energy supplier is, contact them to let them know you have moved in, and submit your meter readings, taking pictures for evidence²³. You can start the process as soon as you become responsible for the property, for example after exchanging contracts when buying²³. If the home has a prepayment meter, contact your energy supplier at least three days before moving in to ask whether the meter needs resetting or whether you need a new key or card²⁴.

Moving is also one of the times a manual meter reading is genuinely needed, even with a smart meter: you might need to take one if you switched suppliers, if you moved, or if your supplier cannot take automated reads⁶. Our page on meter readings when moving home covers the detail.

What if you are on a fixed tariff when you move? Your supplier might let you keep the same contract and tariff at your new home without charging a fee, so it is worth asking before you assume the deal is lost²². If you break the contract instead, you will automatically go onto a standard variable tariff in your new home²².

The switching process, from quote to closing bill

The sequence from start to finish runs as follows.

1. Gather your details. You need your postcode, the name of your current supplier, the name of your current tariff, the amount you pay per unit in kilowatt hours, and the amount of energy you use each year³. Independent guidance lists the same set: your current supplier and tariff, your annual usage or costs, all from your latest bill¹².
2. Compare quotes. Use the unit rates, standing charges, contract length and exit fees to compare like with like¹¹.
3. Choose and apply. Once you pick a deal, the new supplier contacts your existing supplier on your behalf, arranges your switch date and asks for a final meter reading¹¹.
4. Cooling-off period. You have 14 days at the start of the new contract during which you can change your mind, with no exit fee².
5. The switch date. Suppliers must switch your electricity or gas supply from your old supplier to your new supplier within five working days³, a standard in force since 1 April 2024⁴. Your supply is not interrupted².
6. The final bill. Your old supplier sends a final bill, which should arrive within six weeks. Any amount you owe is added to it².
7. Claim your credit. If you are in credit with your current supplier, make sure you claim the money back from them when you switch¹. Your old supplier will refund any credit in your final bill, and you could get compensation if they do not⁵.

If you have separate suppliers for gas and electricity and want smart meters installed, you will need to book individual appointments with both, and it is recommended that you change your electricity meters first²⁵. Our guides on taking a meter reading and submitting readings to a supplier cover the reading steps in detail.

Those barred from switching or from some tariffs

Some households face hard limits, and it is better to know them before comparing deals.

• Tenants whose landlord pays the energy supplier cannot switch supplier or tariff themselves. If your landlord pays the energy company, they choose the supplier; you can ask them to change, but they do not have to²⁶. If you pay the supplier directly, including with a prepayment meter, you can switch²⁶.
• Residents on a landlord's business contract may not have the right to choose their own energy supplier or switch suppliers themselves²⁷.
• Prepayment customers with debt cannot switch the fuel they owe on if the debt exceeds £500: Ofgem's guidance is that you can switch if you have a prepayment meter and owe your supplier up to £500³, and the same £500 limit appears across independent guidance². You can still switch the other fuel. Once the debt is settled, the supplier may be able to change the prepayment meter to a credit meter¹⁷.
• Economy 10 customers cannot compare through at least one major comparison service, which does not support Economy 10 switching; the guidance is to go directly to suppliers to see which tariffs are available¹⁷.
• Heat network customers have protections rather than full market choice: under draft consumer protection guidance, when a supplier switches an existing supply meter to prepayment mode without the consumer's consent, it must ensure the consumer receives prepayment meter credit, unless that is technically infeasible²⁸.

Being on a prepayment meter is not itself a barrier: it does not prevent customers from switching tariff or supplier²⁴. Moving from prepayment to a credit meter is possible, though in most cases you need to pass a credit check or pay a refundable deposit, and private tenants who are the bill payer have the right to change payment method²⁴. Switching from an existing prepay meter to a smart credit meter is described as straightforward by the smart meter network operator²⁵. Our page on switching with a prepayment meter and debt covers the detail.

One further limit concerns meters rather than tariffs: only under exceptional circumstances would an energy supplier be expected to change a smart meter back to a traditional meter, and the supplier may charge the costs if it agrees²⁹.

Incentives, and the limits of a switch

Suppliers compete on more than the unit rate. When you compare, the factors worth weighing include customer service and support, and additional benefits or incentives¹¹. Some suppliers offer advice on more efficient use of energy that could help you cut your bills³⁰, and efficiency programmes in Wales have included making sure people know how to switch supplier to save money as an explicit aim³¹.

The most reliable "incentive" is your own money: if you are in credit with your current supplier, claim it back when you switch¹, and your old supplier must refund any credit in your final bill, with compensation available if they do not⁵.

What a switch will not do is equally important. It will not change the energy you receive¹, it will not reduce how much energy your home uses, and it will not end your dependence on the grid, on gas, or on a supplier's future pricing. A cheaper tariff lowers the cost of the energy you buy; only efficiency measures, and eventually generation of your own, change how much you need to buy. Our page on taking more control of your home's energy sets out that wider picture.

Different tariff rules apply in Northern Ireland

The switching market described above is the GB market, regulated by Ofgem. Northern Ireland has its own arrangements, and the differences are written into legislation. Under the ministerial direction made under section 22 of the Energy Prices Act 2022, each licensed electricity supplier in Northern Ireland shall not set a new tariff or revise an existing tariff for any consumer to take effect on a day other than a quarter day, unless it has the written consent of the Secretary of State³². That restriction on when prices can change is a structural difference from the GB market, where the price cap moves every three months⁴.

For households in Northern Ireland struggling with bills, nidirect sets out the support available from suppliers, including offering advice on more efficient use of energy that could help cut bills³⁰. The practical steps of a switch, the meter reading and the final bill, work in broadly the same way, but the tariff landscape you are comparing across is a different one, and comparison services built for GB suppliers will not give a full picture of the Northern Ireland market.