How switching works

Switching energy supplier is mostly an admin change. Your new supplier takes over the billing, your old supplier closes their account and the pipes, wires, meter and physical supply stay the same.

Reviewed 25 May 2026: Ofgem says a domestic switch should take up to five working days once the switch is under way. Citizens Advice says you can ask for the switch as soon as possible or after the 14-day cooling-off period. Octopus says it usually switches new customers within three working days, unless you ask it to delay. If you are ready to move to Octopus, our step-by-step switching guide covers the signup flow.

Source check, 25 May 2026

The current source check for this page used Ofgem’s switching guidance, Ofgem’s switching-compensation page, Citizens Advice switching advice, Octopus’s switching help and Octopus’s guaranteed-standards page. The practical points are:

• Ofgem says household supplier switches should complete within five working days once they start, and you can ask for a later switch date.
• Citizens Advice says the new supplier contacts the old supplier, you get a 14-day cooling-off period and you can choose either an as-soon-as-possible switch or a switch after that cooling-off period.
• Octopus says it usually switches new customers within three working days, but the wider five-working-day standard is the safer deadline to use if something is delayed.
• Final bills and closed-account credit refunds have their own standards: the old supplier should send the final bill within six weeks and refund remaining credit within 10 working days after the final bill.
• If the switch is late, wrong or mishandled, current Ofgem and Octopus guidance points to £40 automatic compensation in several common switching and closed-account cases.

Nothing physical changes at your home

No engineer normally visits just because you change supplier. Nobody changes your boiler, consumer unit, cables or gas pipes. Electricity still arrives through the local network and gas still arrives through the same gas network.

The change is about responsibility for your account. Octopus becomes the company that bills you, takes readings, sets your Direct Debit and handles your tariff.

The usual switching timeline

The exact timings depend on the switch date you choose and whether the industry data is clean, but the normal process looks like this:

Before you start: Have a recent bill or online account to hand. Your new supplier may ask for your postcode, current supplier, current tariff, annual use, payment details and sometimes your meter details.

Signup day: You choose a tariff, enter your details and agree the contract. Your new supplier then contacts your old supplier through the central switching process. You do not normally need to call your old supplier to say you are leaving.

Cooling-off period: Domestic energy contracts have a 14-day cooling-off period. Some people choose to switch as soon as possible, which can still be within that period. Others ask for the switch to happen after the cooling-off period ends.

Switch date: For a household switch, Ofgem says the switch should take up to five working days once it starts. Octopus says it usually switches new customers within three working days, unless you ask for a delay. Take a meter reading on the day of the switch if you can, especially if your smart meter is not already sending reliable readings.

After the switch: Your old supplier sends a final bill. Ofgem says the old supplier should send that final bill within six weeks and refund any remaining credit within 10 working days of the final bill.

For what happens once Octopus has taken over, read your first month with Octopus.

Will the lights go off?

No. A supplier switch does not disconnect your home. The supply remains live while the account changes hands.

Problems can still happen with data, final bills or smart meter communication, but those are billing and metering issues rather than a loss of supply. If you ever have an actual power cut or gas emergency, use the emergency network routes, not your switching paperwork.

If the switch is delayed

Ofgem’s guaranteed standards cover delayed switches, mistaken switches and final-bill problems. Current guidance says you may be owed automatic compensation if a supplier misses the relevant deadline. The listed amount is now £40 for several switching and closed-account standards, including late switches, late final bills or late credit refunds.

You should not need to fight for this in ordinary cases, but it is still worth keeping the signup confirmation, switch-date messages, final bill and any meter readings in one place.

What your old supplier does

Your old supplier closes your account and sends the final bill. If you were in credit, they should refund you after that final bill. If you owe money, you still need to pay it, even though the supply has moved.

A debt on a normal credit meter does not automatically stop every switch, but the old supplier can still pursue the balance. Prepayment meter debt has separate rules and can sometimes move with you under the Debt Assignment Protocol if it is below the current threshold. If debt is part of the reason you want to switch, get advice before relying on a quick supplier change to solve it.

If you are near the end of a fixed tariff, check the exit-fee window before you start. Citizens Advice says fixed-tariff customers can usually switch without an exit fee when they have 49 days or less left on the contract, while leaving earlier can still mean a fee unless the supplier or tariff says otherwise.

What happens to smart meters

A SMETS2 smart meter should usually keep its smart functions after a switch, although it may take a little while for the new supplier’s systems to settle. Older SMETS1 meters can be less predictable and may temporarily behave like traditional meters until they are enrolled or upgraded.

Octopus also says a newly installed smart meter and in-home display can take up to 14 days to connect after installation. That is not the same as the supplier switch itself, but it explains why readings or app data can lag for a while.

If readings do not look right, keep manual readings and photos until the account has settled. Our guide to what happens to your smart meter when you switch goes into the meter side in more detail.

Can renters switch?

Usually, yes. If you pay the energy supplier directly and have your own meter, you normally choose the supplier. Your tenancy agreement might say you should tell the landlord, but it should not usually stop you choosing a supplier.

The main exception is where energy is included in rent or supplied through a landlord, building operator or heat network. In that setup you may not have a normal domestic supply contract to switch.

A sensible switching checklist

Before switching, check:

• whether your current tariff has exit fees
• whether you want the switch as soon as possible or after the cooling-off period
• whether the new tariff needs a smart meter, an EV, solar export or a compatible charger
• whether you have recent meter readings or photos
• whether your old account is in credit or debt
• whether a fixed tariff is close to ending, where a specific switch date may matter

If you decide Octopus is the right fit, you can use Matt’s Octopus referral code when you sign up. It should still be a tariff decision first, not just a code decision.