Switching mechanics across suppliers

Switching a domestic gas or electricity supplier changes the company that bills for energy. It does not change the local pipes, cables or network operator, and the supply is not disconnected while the account moves.

The new supplier runs the transfer. The customer still has important jobs: compare the actual tariff rather than the monthly direct debit, check that the meter and connected equipment are supported, preserve the opening reading and treat export payments as a separate contract.

The timings and compensation figures below are the rules current as at 22 July 2026.

Before applying

Collect the information from the latest bill or account:

• current supplier and tariff name
• unit rates, standing charge and any time bands
• annual gas and electricity use in kWh
• tariff end date and contractual exit fee
• meter type, payment method and whether it is operating in credit or prepayment mode
• electricity and gas meter-point details where shown

For a time-of-use home, also check:

• whether the new supplier supports the smart meter in its current mode
• whether the tariff requires a named EV, charger, battery or heat pump
• who controls the equipment and what happens if its cloud link fails
• whether half-hourly readings and device permissions are required
• the precise cheap-rate times and whether the supplier schedules them dynamically

A low direct-debit quote is not evidence of a cheaper tariff. Compare the standing charge and rates against realistic annual use, including the household’s actual peak and off-peak split.

The switch timetable

Once the customer accepts the new contract, the new supplier contacts the old one and manages the transfer. A domestic customer can choose:

• the earliest available switch, which can take up to five working days
• a switch after the 14-day cooling-off period, which can take a further five working days
• a requested later date, if the supplier can arrange it

The five-day period depends on when the request is made. Ofgem and Citizens Advice distinguish requests made before the supplier’s working-day cut-off from those made later, so use the confirmed switch date rather than counting calendar days yourself.

Take and photograph the meter reading on the switch date. Give it to the new supplier and retain the confirmation. It becomes the boundary between the old supplier’s final bill and the new supplier’s opening account.

Cooling off and cancelling

A new domestic energy contract has a 14-day cooling-off period beginning the day after the contract is agreed. The customer can cancel during that period without an exit fee.

Contact the new supplier immediately and keep written evidence of the cancellation. If the supply has already transferred, cancellation does not mean the electricity used becomes free or that the old contract simply reappears. The new supplier must explain the available routes, which can include agreeing terms with it, returning to the former supplier on equivalent terms where available, or choosing another supplier.

After the cooling-off period, the customer can still switch again, but a valid contractual exit fee may apply.

Exit fees and the end-of-contract window

A standard variable tariff can be left without an exit fee. A fixed-term or specialist tariff may have one, so check the contract rather than relying on the tariff’s marketing label.

For a domestic fixed-term contract, the final 49 days are the protected switching window. A customer can leave during that window without paying an exit fee. With 50 days or more remaining, a valid fee may be charged if the contract permits it.

An exit fee is a cost to include in the comparison, not a general reason for the old supplier to keep the account indefinitely. Compare the fee with the expected saving over the remaining term. Do not use an assumed national “typical fee”, because the actual contract provides the number that matters.

Switching with debt

For a standard credit account, the customer can normally switch if the unpaid bill was sent less than 28 days ago, or if no bill has been sent. The old supplier adds the amount to the final bill. If the bill was sent more than 28 days ago, the old supplier can object until it is paid.

If the amount is genuinely disputed, make a formal billing complaint before applying. Citizens Advice says a supplier that accepts there may be a problem with the bill should allow the switch rather than treating the disputed amount as ordinary arrears.

For prepayment, the Debt Assignment Protocol can move debt with the supply. Under the current rules a customer can switch with up to £500 owed for gas and up to £500 for electricity, subject to the new supplier taking on the debt. Above that level, reduce the relevant debt before applying.

If a switch is blocked, the supplier should explain why. Ask it to identify the bill, date, amount and rule relied upon, then use its formal complaints procedure if the objection is wrong.

Smart meters and data choices

Check smart-mode compatibility before agreeing the tariff. A smart meter that stops communicating still measures energy, but the customer may need to submit manual readings until communications are restored.

The supplier switch can also change the default data-sharing interval. Ofgem’s current smart-meter guidance says a domestic customer who switches after 3 November 2022 normally shares half-hourly data by default, with the option to reduce it to daily. A time-of-use product may depend on the half-hourly data, so ask what reducing the interval would do to eligibility and billing.

Prepayment mode needs a compatible prepayment tariff. Multi-rate, Economy 7 and legacy meter arrangements also need explicit confirmation that the new supplier can bill the correct registers and times.

EV, battery and heat-pump tariffs

An import switch does not necessarily migrate a device integration. Before leaving the old supplier:

1. Export any charging, battery or heating history you need.
2. Record the existing schedules and local fallback settings.
3. Check that the new tariff supports the exact vehicle, charger, battery or heat-pump account.
4. Confirm whether the supplier controls the device directly or reads only the smart meter.
5. Remove the old supplier’s permissions once its service and any final reward calculation have ended.
6. Update programmed tariff windows when the new rates actually begin.

A device can remain scheduled to the former cheap period even though the import account has switched. Conversely, removing the old integration too early can stop a final managed-charging session or prevent evidence being collected for a reward.

Solar export is a separate contract

Changing the import supplier does not itself switch the SEG (Smart Export Guarantee) agreement. Ofgem says the SEG licensee does not have to be the same company as the import supplier.

An existing export agreement can therefore remain where it is if its terms allow. However, some premium or bundled export tariffs require the matching import tariff or a named product. Read both contracts before switching, because leaving the import tariff may reduce the export rate or end eligibility.

If changing SEG as well, run it as a separate process. Preserve the export MPAN, meter details, readings, MCS certificate, grid-connection evidence and the old export contract. Do not assume the import opening reading starts the new export agreement.

Final bill and credit refund

The old supplier must send the final bill within six weeks of the switch. If the closed account is in credit, it must refund the balance within ten working days of sending that final bill.

As at the review date, failure to meet either standard carries an automatic £40 payment by the former supplier. If a required compensation payment is itself not made within ten working days, a further £40 is due.

Check the final bill against the photographed reading, tariff rates, direct debits and any exit fee. Keep the old account open until both the final bill and any credit or compensation have been received.

Delay or mistaken switch

If a requested switch takes more than five working days, the new supplier must automatically pay £40.

If the supply is moved without permission, contact the old supplier and describe it as an erroneous transfer. Ofgem’s current standard allows 21 working days for the supply to be re-registered and provides automatic £40 payments for the initial error and specified further delays. The detailed compensation page should be checked for every missed step rather than assuming there is only one payment.

These domestic switching payments do not apply where the supplier has gone out of business. That situation follows the Supplier of Last Resort process.

When an individual switch is not available

A householder cannot personally choose the licensed supplier where the landlord buys the energy and resells it, or where the property receives heat through a heat network with a common provider. Check who holds the supply contract before comparing tariffs.

Business contracts also have different cooling-off and compensation rules. This page describes a Great Britain domestic supply, not a non-domestic contract merely because the customer happens to work from home.

Complaints

Start with the supplier responsible for the failed step and keep the application, confirmed switch date, readings and correspondence. The supplier must operate a formal complaints process.

The Energy Ombudsman can consider the case after eight weeks without resolution, or sooner if the supplier issues a deadlock letter. The Ombudsman can require corrective action, an explanation or compensation.

Related entries

• How to compare UK energy suppliers
• Export tariff switching across suppliers
• Supplier of last resort process
• Supplier exit and switching for time-of-use tariffs
• Smart meter SMETS2 capability
• GDPR and energy data