How to switch energy supplier in the UK

Why switch, and when it is worth it

Most households that have never switched, or that let a fixed deal roll off, sit on their supplier's standard variable tariff (SVT). The SVT is capped by Ofgem, but the cap is a ceiling, not a good price. A competitive fixed deal, a tracker, or a smart time-of-use tariff can beat it, and a green supplier may be worth a small premium if that matters to you.

Switching is worth a look when any of these is true: you are on an SVT and have never compared; your fixed deal ends in the next seven weeks; you have bought an EV, a heat pump or solar and a specialist tariff would suit you better; or your service has been poor and you want out. It is less likely to pay off if you fixed recently at a rate below today's cap, or if the cheapest deals available carry an exit fee larger than the saving.

Before you switch: what to have ready

You can start a switch in minutes if you have these to hand. None of it is difficult to find.

• A recent bill or online account. It shows your current tariff name, unit rates and standing charge, plus your annual consumption in kWh, the single most useful number for an accurate comparison.
• Your annual usage in kWh for gas and electricity. If you cannot find it, an estimate based on home size works, but the kWh figure gives a far more accurate quote than "typical" bands.
• Bank details for a direct debit. The cheapest tariffs are almost always monthly direct debit (see the direct-debit section).
• Your postcode. Unit rates and standing charges vary across the 14 regional pricing zones, so a fair comparison has to be local to you.
• Any exit-fee details from your current fixed deal, and its end date.

You do not need your meter serial number to start, and you do not need to contact your old supplier. The new supplier arranges everything.

The switch, step by step

Start to finish, a standard switch completes in five working days once your cooling-off period has passed. You will keep supply throughout.

The guarantees that protect you

Two industry commitments underpin every domestic switch, so you are not taking a risk on the process itself.

Exit fees and the cooling-off period

Fixed-term tariffs often carry an exit fee, commonly around £25 to £75 per fuel, if you leave early. Two rules keep this from trapping you:

• The final 49 days are free to leave. Ofgem rules let you switch away in the last 49 days of a fixed contract with no exit fee, so you can line up your next deal before the old one ends rather than being pushed onto the pricier SVT.
• A 14-day cooling-off period. When you agree a new deal, you have 14 days to change your mind and cancel with no penalty. The switch usually completes just after this window closes.

Standard variable tariffs never carry an exit fee, so if you are on an SVT you can leave any time. When a deal does have an exit fee, only switch early if the saving over the remaining term clearly beats the fee.

Pay by direct debit for the best price

Payment method changes the price. Monthly direct debit is nearly always the cheapest way to pay, because it is predictable and cheap for the supplier to administer, and they price that saving in. Paying on receipt of each bill usually costs more per unit, and prepayment can differ again.

How direct debit works in practice: the supplier estimates your yearly cost and splits it into 12 equal monthly payments, so you pay the same in July as in January. In summer you build up credit; in winter you draw it down. This smooths the bill, but it means you should check the balance:

• Give regular meter readings (or use a smart meter) so payments track real use, not an estimate that drifts.
• Watch the credit balance. A large, growing credit in spring means your monthly amount is set too high; you can ask for it to be lowered and the surplus refunded. Some credit going into winter is normal and sensible.
• Whole-amount direct debit (paying the exact bill each month) is an option with some suppliers, but the fixed monthly version is what unlocks the cheapest advertised rates.

Supplier rewards and loyalty schemes

Several suppliers run rewards and loyalty programmes on top of the tariff. They will not turn a bad deal into a good one, but between two similar tariffs they can tip the balance. Check the current terms directly with the supplier before you rely on any of these, as they change.

• Off-peak and demand-flexibility rewards. Some suppliers pay you to shift or cut use at peak times, for example Octopus Saving Sessions, or reward low-carbon behaviour through schemes like Octoplus. If you can move your heavy use (dishwasher, laundry, EV charging) to off-peak, these add up.
• Loyalty and account perks. Programmes such as OVO Beyond or British Gas Rewards offer members extras like tree-planting, prize draws or partner discounts. Treat them as a tie-breaker, not a reason to overpay.
• Referral credit. Most suppliers give both parties account credit (often around £50 each) when you refer a friend. If someone you trust already uses a supplier you were going to pick anyway, use their link.
• Bundled points. White-label brands can layer on a loyalty currency, for example Sainsbury's Energy adding Nectar points, though the underlying supplier is E.ON Next. Compare the real unit price first, then count the points.

Bolt-on tariffs and add-ons

A bolt-on is an optional extra you add to a standard tariff for a fixed monthly fee, rather than a different unit rate. Used well, a bolt-on targets a specific pattern of use; used carelessly, it is a subscription you forget to cancel. The common ones:

• EV charging bolt-ons. Add a cheap overnight rate for your car on top of a standard tariff, useful if a full smart EV tariff does not suit the rest of your home. Worth it only if you charge at home regularly.
• Heat-pump add-ons. A discounted rate for the hours a heat pump runs hardest, offered by a few suppliers, sometimes as a bolt-on rather than a standalone tariff.
• Fixed-price or "capped usage" add-ons. Pay a set fee for a block of energy or to cap a portion of your rate. Read the cap and the exit terms carefully.
• Service and boiler cover. Larger suppliers sell boiler and home-emergency cover alongside energy. It is insurance, not energy; price it against standalone cover before adding it to the bill.

The test for any bolt-on is simple: work out the fixed fee over a year and check your real usage clears it. If it does not, the plain tariff is cheaper.

Making the switch go smoothly

• Photograph your meters on switch day. A dated photo of each reading settles almost any later dispute about where one bill ended and the next began.
• Keep both direct debits open until the final bill from your old supplier is settled and any credit refunded.
• Do not cancel your old direct debit yourself before the final bill clears; let it close naturally, or the refund can stall.
• Set a reminder for your new deal's end date. The saving comes from switching again when the fix ends, not from switching once. Diarise it seven weeks out so you can use the free final-49-days window.
• Check the new tariff is what you agreed on your first bill: tariff name, unit rate, standing charge and payment method.
• Keep your smart meter in smart mode. Switching used to knock some first-generation (SMETS1) meters into "dumb" mode; most have now been enrolled into the national network, but confirm your new supplier can read yours.

Prepayment, debt, renting and moving

• Prepayment meters. You can still switch on prepayment, and you can ask to move to a credit meter, which usually opens up cheaper tariffs. Suppliers must not block a switch unreasonably.
• Owing money. If you owe your supplier less than £500 per fuel, you can still switch under the "debt assignment protocol", and the debt moves with you. Clear larger debts first.
• Renting. If you pay the energy bill directly, you have the right to choose the supplier. If it is included in your rent, the choice sits with your landlord.
• Moving home. Moving is a separate process from switching, with its own steps. See our moving-home energy checklist for meter readings, deemed contracts and switching from day one.

Frequently asked questions