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

Anyone who pays a supplier directly for the gas or electricity used at home can choose to switch to a different supplier or tariff at any time¹. The switch itself is a paperwork exercise: the new supplier manages the transfer, contacts the outgoing supplier, agrees a switch date and asks for a closing meter reading. Suppliers must move an electricity or gas supply from the old supplier to the new one within five working days¹. Nothing physical changes. Switching supplier does not change the energy arriving at the property, only who is paid for it, so no pipes or cables are altered and the supply is not interrupted².

To start, a household needs very little: postcode, the name of the current supplier, the name of the current tariff, the unit price paid per kilowatt hour and the amount of energy used each year¹. Most of that sits on a recent bill or in an online account⁴. The question worth answering before anything else is which tariff the household is on now, because that determines whether an exit fee applies and how much room there is to move.

The limit of the exercise should be stated plainly. Switching changes the commercial relationship, not the household's dependence. The gas and electricity still come through the same network, the same meter and the same supply licence system, and the price on a variable tariff still moves with the price cap. What switching buys is control over which rates apply and for how long.

What switching changes, and what it leaves untouched

The supply is unaffected on both fuels when a switch takes place³. The transfer is handled entirely by the supplier being moved to, under the Energy Switch Guarantee, which also describes switching to a new tariff within five working days whether the change is to a new supplier or a new tariff with the existing one⁷. There is technically no limit to how many times a household can switch³.

What does not change is the physical apparatus and the household's reliance on it. Only the current supplier can move a meter: to have another supplier do it, the supply must be switched to them first⁸. A smart meter cannot normally be swapped back for a traditional one either.

Regulator research found considerably more consumers claiming to be on fixed tariffs (38%) than the official data suggests (11%). 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" confident⁹.

If a supplier fails, no action is required from the customer: the regulator moves the account to a new supplier automatically and the supply is not interrupted¹. A household on a Green Deal loan can change electricity supplier only where the new supplier takes part in the Green Deal scheme¹⁰.

Fixed or variable: which tariff you are on now, and how to tell

The tariff name and details appear on the latest bill or statement, or in a supplier app or online account¹¹. A household is probably on a standard variable tariff if it has never switched supplier, has not switched for a year or more, has had a fixed deal end, or if the tariff name contains words such as "Simpler", "Flex", "Basic", "Standard" or "Variable"¹².

On a variable tariff the unit rate can change at points in the year, influenced by the price cap¹³, and the default variable rate is determined by the energy price cap and changes every three months¹⁴. More bluntly, suppliers "can change prices whenever they like for any reason"¹⁵, though a supplier increasing prices should tell customers in a reasonable amount of time before the change takes effect⁵. A variable rate is simply what the supplier decides to charge per unit¹⁶.

Households are frequently wrong about which they are on. Regulator research found considerably more consumers claiming to be on fixed tariffs (38%) than official data suggested (11%); among those saying they were on a fixed electricity tariff, 55% were "very confident" and 38% only "somewhat" confident⁹. That gap between belief and record is wide enough that confidence alone is no guide. Checking the latest bill, which carries the tariff name and the annual usage, is the only reliable answer.

Fixed tariffs: what is locked in and what still varies

On a fixed tariff the unit cost of energy and the daily standing charge are fixed; the amount charged still depends on how much energy is used, multiplied by that unit cost, plus the daily fee⁵. A fix locks in unit rates and standing charges, not the total bill, which changes with consumption¹⁷. Fixed and standard variable tariffs share one feature: energy costs the same at any time of day¹³, unlike time-varying tariffs.

Fixed deals normally run a minimum of 12 months, and are commonly 12 to 24 months¹⁴. The trade-off is flexibility: a fixed deal usually ties the household in for a set period¹⁸. Most fixed tariffs include exit fees for each fuel, payable on leaving early¹⁹. Consumer understanding here is patchy: only 57% could identify that exit fees may still apply when moving to another deal with the same supplier⁹.

If a fixed tariff has already ended, switching supplier or tariff remains open at any time⁵.

What a fixed deal costs against the price cap

No single published saving figure exists, because fixed prices are quoted deal by deal by each supplier. What the evidence supports is a direction of travel: standard variable tariffs are described as the most expensive tariff an energy consumer can be on, with fixed rates usually the cheapest²⁰, and a supplier moving a household onto its standard variable tariff at the end of a fix moves it onto a rate that is typically higher than fixed rates²¹.

Comparisons should weigh unit rates and standing charges, whether prices are fixed or can change, the length of any fixed term, the payment methods available, customer service and support, and any additional benefits or incentives¹¹. A fixed rate is only worth taking where it is no more than 40% more expensive than the current price cap, on one independent assessment²⁰.

Separately, and for households willing to shift their usage rather than simply change rates, regulator modelling estimates that those who do not generally use electricity at peak times of 4pm to 7pm could save over £200 a year by moving from the price cap to a tariff whose price changes through the day²². That is a different proposition from a fixed deal and depends on being able to move consumption.

Exit fees and the 49-day penalty-free window

An exit fee may be payable to a previous supplier where a fixed rate tariff was left before it ended¹. The exception is the run-up to the end date.

The 49-day rule is consistent across the sources: a provider cannot charge exit fees if a switch happens within 49 days of the current deal ending²⁶, described elsewhere as 49 days or seven weeks²³, and customers are entitled to switch from 49 days before the end of their contract²⁷. Suppliers should not charge any exit fees from 49 days before the plan end date²⁸.

Fees change behaviour. In regulator research, 93% of consumers who thought they had an exit fee said they would take a deal with no exit fee, against 70% for a deal carrying a £300 exit fee⁹. A supplier also cannot charge an exit fee to switch after it has said a switch may go ahead⁵.

When a fixed deal ends, the rollover is automatic

Nothing needs to be done for a fixed deal to end badly. The supplier automatically moves the account onto its standard variable tariff when the fixed deal ends⁵, and that tariff is generally more expensive¹². Customers who do not sign a new deal are rolled onto the supplier's standard variable tariff²⁷; some suppliers may instead offer the chance of another fixed deal¹⁷.

The warning is built into the rules. A supplier is required to contact a fixed-term customer 42 to 49 days before the end date, saying the tariff is ending⁶, and that obligation is described elsewhere as notice 49 to 42 days before²³. A supplier should also remind customers when a contract is about to end⁵. Treating the switch as a habit every 12 to 18 months keeps the account off the default rate²⁷.

Moving home: the tariff you inherit and the opening reading

On moving in, the household is automatically put onto a deemed contract with the property's existing supplier, on that supplier's default or standard variable tariff²⁹. The move itself is an automatic switch to the new property's supplier, and the tariff will probably change³⁰.

For a household already on a fixed deal at the old address, a supplier might allow the same contract and tariff to continue at the new home without a fee; if the contract is broken, the household goes onto a standard variable tariff at the new property²⁹. The right to switch begins as soon as responsibility for the property begins, which when buying is after exchange of contracts³¹.

The practical sequence on moving day is short: identify the supplier, tell them the household has moved in, and submit meter readings, keeping photographs as evidence³¹. A meter reading is needed when switching suppliers, when moving, and where a supplier cannot take automated reads²⁶. That opening reading is what separates the previous occupier's consumption from the new household's. Guidance on meter readings when moving home and on taking a meter reading covers the mechanics.

Where the home is supplied through a business contract, checks before moving in should cover who holds the energy contract, how charges are calculated, how much residents typically pay, whether charges are metered or estimated, whether the supplier or tariff can be chosen, and whether it is possible to switch to a domestic contract³². Moving into a home with a prepayment meter warrants contacting the supplier at least three days before moving in, to ask whether the meter needs resetting or a new key or card is required³³.

Switching step by step, from quote to final bill

1. Gather the details. Postcode, current supplier, tariff name, unit price per kWh and annual consumption¹. Some comparison routes ask only for an address and a recent bill³⁴, or postcode, plan name and a recent bill³⁵.
2. Check the exit fee position. Note the tariff end date and whether the account is inside the final 49 days²³.
3. Compare on rates, not headline claims. Unit rates, standing charges, contract length, payment methods and any incentives¹¹.
4. Confirm the switch with the new supplier. The new supplier manages the transfer³⁶, contacts the existing supplier, arranges the switch date and asks for a final meter reading¹¹.
5. The cooling-off period runs. No exit fee can be charged for switching tariff during the 14-day cooling-off period at the start of the contract³.
6. Take a reading on the switch date. A reading on the day of the switch is part of the process³⁷.
7. Settle the closing account. Any amount owed is added to the final bill from the old supplier, which should arrive within six weeks³. Credit on the account is refunded by the old supplier in the final bill, with possible compensation if it is not³⁸; credit should be claimed back on switching².

The whole transfer between tariffs or suppliers is handled by the supplier being moved to³⁶, and the process should be completed within five days once the switch is confirmed³⁵. Since April 2024, suppliers have five working days to move a household from the old supplier to the new¹⁴.

Who cannot switch, or cannot reach every tariff

Switching is straightforward for a household on a variable rate tariff, or one whose fixed contract is ending shortly⁴. Several groups face limits.

• Tenants whose landlord pays the supplier. They cannot switch supplier or tariff themselves; the landlord chooses the supplier and can be asked to change, but does not have to⁴¹. Tenants who pay the supplier directly can switch, including with a prepayment meter⁴¹. See switching supplier if renting.
• Residents on a landlord's business contract. They may not have the right to choose their own supplier or switch themselves³².
• Prepayment customers in debt. Switching is blocked above £500 owed for gas or £500 for electricity⁴⁰; below that, the debt can be repaid to the new supplier [10 words apply: see below]⁴².
• Economy 10 households. At least one comparison service does not support Economy 10 switching, directing customers to approach suppliers directly¹⁹.

On prepayment debt, Ofgem puts the threshold at up to £500 owed per meter¹, and independent guidance agrees that switching is possible while debt to the current provider is under £500⁴³. Being on a prepayment meter does not in itself prevent switching tariff or supplier, and tenants responsible for the bills keep the right to switch³³. Where the account debt is settled, a supplier may be able to change a prepayment meter to a credit meter¹⁹; some suppliers install a new meter free, but in most cases a credit check or a refundable deposit is required, and private tenants who are the bill payer have the right to change payment method³³. Further detail sits on switching supplier with a prepayment meter and debt.

Smart meters are not an obstacle. People with a smart meter can switch supplier and tariff in exactly the same way as anyone with a traditional meter¹³, and many prepay customers can switch supplier while keeping their smart meter, with the supplier able to change between credit and prepay modes without a whole new meter⁴⁴.

Incentives, and what a switch will not do

Extra rewards for switching are unusual: a small cashback sum may occasionally be offered for moving to a specific supplier³⁷. Some comparison services require only a postcode and tariff name to start³⁰. Suppliers also offer advice on using energy more efficiently as a way of cutting bills⁴⁵, which is a different lever from the tariff itself.

It is worth being clear about the ceiling. Aside from switching, a household does not control the tariff its supplier sets; what it can change is how much energy it uses. Rates, standing charges, cap movements and end-of-contract rollovers all remain in the supplier's and the regulator's hands. Reducing demand, and where possible shifting it, is the part of the bill a household actually owns. The wider sequence is set out in taking more control of your home's energy and in the home energy how-to guide.

Northern Ireland works to different tariff rules

Northern Ireland's domestic electricity market is governed separately. Under a 2022 ministerial direction, each licensed electricity supplier "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" without the written consent of the Secretary of State⁴⁶. The effect is that tariff changes there are pinned to fixed points in the calendar rather than being made at any time. Support for households struggling to pay in Northern Ireland includes suppliers offering advice on more efficient energy use to help cut bills⁴⁵. The switching process described above reflects Great Britain's arrangements, and households in Northern Ireland should expect their supplier's tariff timetable to differ.