Does it cost anything to switch energy supplier?

That fee is real and it is set by the tariff, not by the switch. Exit fees are typically £100 or more, and often around £100 per fuel, so a dual fuel household leaving a fixed deal early could face a bill on both gas and electricity³. Ofgem's own guidance is blunt about when it applies: you may have to pay your previous supplier an exit fee if you were on a fixed rate tariff and chose to leave before it ended¹.

The rest of the picture is protective. Suppliers must complete a switch within 5 working days, and if they do not, the new supplier must pay you £40¹. Supply is not interrupted, no one needs to visit, and the Energy Switch Guarantee commits signatory suppliers to a set of promises covering the process⁴.

What the switch itself costs, and who pays

Nothing is charged for switching. The Energy Switch Guarantee describes switching your energy as free of charge, with the caveat that an exit fee may apply depending on your tariff². Independent guidance is the same: there is no charge to compare and switch your energy⁴. One supplier's own guidance states plainly that changing electricity supplier is free of charge⁷.

The reason there is no fee is structural. The switch happens at an administrative level between suppliers, so your energy service is never disrupted and no cables or pipes are replaced⁸. There is no physical work to bill for. The new supplier contacts your existing supplier on your behalf, arranges the switch date and asks for a final meter reading⁹. That administrative handling is part of what the Energy Switch Guarantee formalises: the whole transfer between tariffs or suppliers is handled by the supplier of the tariff you are moving to⁵.

Where money does change hands, it is usually compensation rather than cost. If your supply is switched by mistake, you could get £40, and you will automatically get £40 in compensation from the new supplier¹. If your old and new suppliers take more than 20 working days to decide whether a switch was correct, you get £40 from each of them³. If a switch takes longer than the 5 working days allowed, the new supplier must pay you £40¹.

One related move is also free at the largest suppliers: none of the biggest energy suppliers charge to swap from prepayment to standard credit¹¹. That is a meter and payment change rather than a supplier switch, but it is the other common transaction households ask about.

Exit fees: when your tariff charges you to leave

An exit fee is the amount you will be charged by your energy supplier if you want to leave your contract early¹². It applies to fixed rate tariffs, where you agreed a term in exchange for a rate. Fixed energy tariffs usually run 12 to 24 months, and leaving before the end is what triggers the charge³.

The amounts vary by tariff and supplier. Independent guidance puts exit fees typically at £100 or more, and notes they are often around £100 per fuel if you want to leave before the end of your contract³. A worked example from a bill reading shows a customer on a deal with exit fees of £50 per fuel, electricity and gas, payable if they switched before the final 49 days of the contract¹³. That is a single example, not a market rate, but it shows how the per fuel structure works in practice.

Several conditions remove the fee entirely:

• You cannot be charged an exit fee if you switch tariff during the 14-day cooling-off period at the start of the contract⁶.
• Your provider cannot charge exit fees if you switch within 49 days of your current deal ending¹⁴.
• A supplier cannot charge you an exit fee to switch supplier after they said you can switch, and cannot charge you a fee to switch supplier if your contract ends in the next 7 weeks¹⁵.
• If you are moved to a new supplier because your old one failed, you can switch again without any exit fees, even if you were previously on a fixed contract¹⁶.

Two things catch households out. First, exit fees can apply even if you switch to a new deal with the same supplier, so an internal move is not automatically free¹⁸. Second, the fee can apply on any defined length tariff, paid if you switch to a different tariff more than four weeks before the tariff end date¹⁹. The four week and 49 day figures come from different documents and describe the same protection window in slightly different terms.

The decision itself is a comparison, not a rule. Guidance is to compare the exit fee with the savings you could make by switching, because moving to a cheaper tariff could still save money overall⁹. Ofgem research found that among consumers who thought they had an exit fee on their current contract, 70% would switch to a £300 exit fee deal²⁰. The fee is a factor in the decision, not a bar to it.

How the Energy Switch Guarantee protects the process

The Energy Switch Guarantee is a voluntary set of promises that suppliers sign up to⁴. It is essentially a list of 10 commitments that protect households throughout their switch⁴. Because it is voluntary, it binds the suppliers that have signed up and not the rest of the market, which is why the statutory protections from Ofgem sit underneath it.

The commitments that matter most to a household are these:

• The whole transfer between tariffs or suppliers is handled by the supplier of the tariff you are moving to⁵.
• Your old and new supplier communicate about the switchover date so there is no overlap in the billing periods and you are not charged twice².
• Both old and new suppliers work together to ensure your supply will never be interrupted²¹.
• Switching to a new tariff is possible within just 5 working days²².

The double charging protection is the one households worry about most, because a badly timed switch can otherwise produce two bills covering the same days. The guarantee states that you will not be charged twice for the gas and electricity you use⁴. The 5 working day commitment matches the statutory deadline: suppliers must switch your electricity or gas supply from your old supplier to your new supplier within 5 working days¹.

Individual suppliers advertise their adherence. EDF Energy states that its tariff changes are backed by the Energy Switch Guarantee²³. That is a maker's claim about its own product, and it tells you the supplier has signed up, not that the guarantee covers the whole market.

What actually happens during a switch

The process is short and largely invisible. The new supplier contacts your existing supplier on your behalf, arranges the switch date and asks for a final meter reading⁹. You do not need to give notice to your current supplier for an ordinary switch; the transfer is arranged for you. Notice requirements belong to moving home, where at least 48 hours' notice to the current supplier applies, and you can notify well in advance²⁴.

Supply is not interrupted. Both gas and electricity supply should be unaffected when you switch from one supplier to another⁶. The Energy Switch Guarantee's promise that both suppliers work together so supply is never interrupted is the same assurance in contractual form²¹.

The switch should take up to five working days, and it should not take more than 5 working days, though you can ask to delay it²⁶. If the deadline is missed, the £40 payment from the new supplier applies¹.

A few situations change the shape of the process:

1. Moving home. When you move, you are automatically switched to the new property's supplier, and your tariff will likely change²⁷. An exit fee can apply if you are on a fixed tariff and break the contract early²⁸.
2. Switching with a debit balance. If your account is in debit or you still owe money to your old supplier, you can still switch energy suppliers, but you will receive a final bill which must be paid in full²⁹.
3. A recent meter change. If you switch to a new supplier within 12 months of a non-smart credit meter being fitted, the supplier might charge you, even if the meter was fitted for free³⁰.
4. Renters. If you are directly responsible for paying your energy bill, you are able to switch⁶. If the cost of your energy is included in your rent, the landlord is responsible and a switch is arranged through them²¹.
5. Supplier failure. You do not need to do anything if your current supplier goes out of business; Ofgem moves you automatically to a new supplier and makes sure your energy supply is not interrupted¹. You can then switch to another supplier without any exit fees¹⁶.

Where the cost question gets complicated

The simple answer, that switching is free, holds in most cases. The exceptions are worth knowing before committing.

The first is the fixed tariff exit fee, covered above. The second is the timing of a move. The third is the state of the market itself. Guidance from a consumer organisation notes that due to the current crisis in energy prices, you may not save money by switching and might be better off sticking with your current supplier³¹. That is a statement about savings, not about cost: the switch is still free, but a free switch to a more expensive tariff is not a saving.

There is also an unresolved point in the compensation rules. Independent guidance describes a £40 payment if your old supplier does not issue your final bill within 6 weeks of a switch, and separately a £40 payment if your new supplier takes longer than 5 working days to switch you⁶. Where a switch goes wrong, the guaranteed standards and the Energy Switch Guarantee both point to £40, but the exact trigger depends on what failed.

For a household thinking about energy independence, the switch is the cheapest lever available. It costs nothing to move supplier, the process is bounded at 5 working days, and the protections are written down. What it does not change is the underlying dependence: you remain connected to the same grid and the same pipes, and you remain reliant on whichever supplier holds your account, its billing systems and its customer service. Switching changes who you buy from and on what terms. It does not change where the energy comes from or how it reaches the house.