If you’re wondering how to switch energy supplier in the UK, the mechanics are genuinely simple. Most switches now complete in two to five working days, your supply doesn’t get interrupted, and your new supplier handles the whole handover with your old one. You barely have to do anything.
The tricky bit is everything around it. Knowing whether you’ll actually save money, what to look for in a deal, and what to do if something goes wrong. This guide walks you through all of that, step by step.
Switching supplier update for April 2026
One thing worth flagging before we get into the how. The war in Iran and the ongoing closure of the Strait of Hormuz have sent UK wholesale gas prices up sharply since late February, suppliers have been pulling and repricing fixed tariffs daily, and the July price cap is expected to rise significantly. The April cap at £1,641 is artificially low because it was set before the crisis hit. This changes the calculation on whether switching makes sense for your situation, and it deserves its own piece rather than a rushed paragraph here.
If you’re still working out whether now is the right time, head to [Should I Switch Energy Supplier in 2026?] before you come back to the how-to. If you’ve already decided you want to switch, carry on.
How energy switching actually works
Here’s the thing most people get wrong. When you switch supplier, nothing physical happens. The same gas comes down the same pipe. The same electricity travels along the same wires. No one visits your house. No one cuts anything off. The only thing that changes is the company that sends you a bill.
That’s it.
The switching process is governed by the Energy Switch Guarantee, a voluntary commitment that all the major suppliers have signed up to. It says switches should complete within five working days, your supply won’t be disrupted, and if your old supplier owes you money they’ll refund it within two weeks of sending your final bill.
You also get a 14-day cooling-off period, by law. This starts the moment you sign up to the new deal. Inside those 14 days, you can cancel for any reason (or no reason) without penalty. Under the current rules, the switch itself can actually complete during the cooling-off window, so you might be on supply with your new provider before the 14 days are up. You can still cancel.
If you’re new to the whole tariff thing, our [Energy Tariffs Explained: A Complete Guide for UK Bill Payers] covers the basics before you go any further.
Before you switch: what you need to know about your current deal
This is the bit people skip, and it’s the bit that actually matters. Without these numbers, any comparison you run is essentially a guess.
You need four things:
Your current tariff name. Not just “British Gas” or “Octopus”. The actual tariff. Something like “Flexible Octopus” or “Standard Variable” or “Fix and Fall May 2026”. It’ll be on your latest bill or in your online account.
Your unit rate and standing charge. The unit rate is how much you pay per kilowatt hour of energy, in pence. The standing charge is what you pay every day just to be connected, regardless of whether you use anything. Both are on your bill. You’ll have separate figures for gas and electricity.
Whether you’re in a fixed contract and if so, what the exit fee is. If you’re on a fixed deal that hasn’t ended, leaving early usually costs you. Exit fees are typically applied per fuel, so dual-fuel customers can get hit twice. There’s an exception: during the final 49 days of your contract, you can switch without exit fees. That’s the “switching window” and it’s worth knowing about.
Your annual usage in kWh. Not your annual spend in pounds. The actual kilowatt hours. This is on your bill too, usually near the back. Typical UK homes use around 2,700 kWh of electricity and 11,500 kWh of gas a year, but yours might be very different. If you guess this figure, every quote you get will be wrong.
Got all four? Good. Now you can actually compare things meaningfully.
How to compare deals properly
This is where a lot of switching advice falls apart. Comparison sites are useful, but they’re not neutral, and “cheapest” is often not what you think it is.
Comparison sites vs going direct
Ofgem accredits a handful of comparison sites that agree to show you every deal available at your postcode, not just the ones they earn commission from. The Citizens Advice energy comparison tool lists accredited sites, which is where to start. Unaccredited comparison sites often only show deals from partner suppliers, which means the “cheapest” on their list might not be the cheapest on the market.
Going direct to a supplier’s website is fine too, especially if you already know who you want. You’ll just be comparing that one supplier against your current deal rather than the whole market.
Headline unit rates lie
Suppliers love advertising cheap unit rates, then quietly whacking up the standing charge. Over a year, a slightly higher unit rate paired with a much lower standing charge can easily be the better deal, especially for low users. Always look at the estimated annual cost, not the unit rate.
For dual-fuel customers, also check whether the deal is genuinely dual fuel or whether you’re being quoted gas and electricity on separate tariffs from the same supplier. It usually doesn’t matter, but occasionally the maths works out better if you split your gas and electricity across different suppliers. Rare, but it happens.
Fixed vs variable vs tracker
A fixed tariff locks your unit rates and standing charges for a set period, usually 12 or 24 months. You’re protected from rises but you don’t benefit from falls. Most fixed deals have exit fees.
A variable tariff (usually the standard variable tariff, or SVT) tracks the price cap. Prices change every quarter when Ofgem reviews the cap. No exit fees, no protection.
A tracker tariff follows wholesale energy prices or the price cap directly, often with a small discount built in. Octopus Tracker is the best-known example. Prices can change daily. Good for people who want to bet on wholesale prices falling, risky if you don’t.
Then there are time-of-use tariffs like Economy 7 and smart tariffs such as Octopus Agile, which charge different rates at different times of day. Useful if you can shift consumption to off-peak hours (EV charging, dishwashers on timers, heat pump use), terrible if you’re home all day and can’t.
What “green” actually means
“100% renewable electricity” on a tariff usually means the supplier has bought Renewable Energy Guarantees of Origin (REGOs) equivalent to your usage. It doesn’t necessarily mean they built wind farms or generated the electricity themselves. Some suppliers (Ecotricity, Good Energy, Octopus) genuinely invest in renewable generation. Others buy REGOs on the wholesale market, which is cheap and mostly symbolic. If this matters to you, dig into how the supplier actually sources its energy, not just what the tariff is labelled.
Summary: current competitive suppliers at a glance
These are the suppliers most worth looking at in 2026. This isn’t a full market list, and specific tariffs change constantly, so treat this as a starting point rather than a final answer.
| Supplier | Typical tariffs available | Customer service (Citizens Advice, Q4 2025) | Smart meter support | Standout feature |
|---|---|---|---|---|
| Octopus Energy | Fixed, tracker, smart/EV tariffs | Strong (top among Big Six, 3.77 ★) | Excellent, full SMETS2 | Referral scheme, EV and smart tariffs, strong app |
| E.ON Next | Fixed, variable, smart tariffs | Strong (second among Big Six) | Good | Wide tariff range, competitive fixes |
| EDF | Fixed (1–3 year), tracker, FreePhase | Mid-table | Good | Longest fixed deals, static and dynamic tracker options |
| Ecotricity | Green variable, fixed | Top-rated in sector (3.93 ★) | Good | Strongest customer service, genuine green investment |
| British Gas | Fixed, variable, tracker | Below average (2.28 ★) | Good, broad rollout | Size, reliability, engineer network |
| OVO Energy | Fixed, variable, EV tariffs | Mid-table | Good | Competitive EV tariffs |
| Good Energy | Green fixed and variable | Generally strong | Good | Fully renewable, small supplier feel |
For a deeper look at individual suppliers, see our best UK energy suppliers guide.
The step-by-step switching process
Right, to the actual process. This is how you do it.
Step 1: Gather your details
You need: your full address and postcode, your current supplier and tariff name, your annual usage in kWh for gas and electricity (from your bill), a recent bill to hand, and your bank details for the new Direct Debit. Takes five minutes if your paperwork is tidy. Longer if you haven’t looked at a bill in a year.
Step 2: Run a proper comparison
Use an Ofgem-accredited comparison site (Citizens Advice lists them), or go direct to two or three supplier websites. Plug in your real numbers, not estimates. Look at the estimated annual cost, not the headline unit rate. Note the tariff length, exit fees, and any smart meter requirements.
Step 3: Choose a deal, and check the small print
Before you commit, check: how long is the fixed period, what are the exit fees, does the tariff require a smart meter, is there a Direct Debit requirement, and what happens at the end of the term (do you auto-roll onto another fix, or drop onto the variable rate)? Most tariffs quietly roll you onto the standard variable rate when the fix ends, which is usually the price cap. Set a diary reminder for a month before expiry.
Step 4: Apply
You apply through the new supplier, either online or by phone. They handle everything with your old supplier. You don’t need to contact your current provider at all. You’ll get a welcome email and a confirmed switch date.
Step 5: The cooling-off period and meter reading
You’ve got 14 days from signing to change your mind with no penalty. Use them to actually read the terms. On the day the switch goes live (or just before), take a meter reading and submit it to both suppliers. If you have a smart meter, this usually happens automatically, but a manual reading as backup does no harm.
Step 6: Switching day
Nothing dramatic happens. Your supply stays on. The new supplier takes over billing from the switch date. You might not even notice the day it happens.
Step 7: Final bill from your old supplier
Your old supplier sends a final bill within six weeks. If you’re in credit, they refund you within 14 days of that final bill. If they miss either deadline, you’re automatically entitled to compensation (currently around £40 per missed deadline, though check the latest figures as Ofgem reviews these).
Common pitfalls and how to avoid them
Most switches go fine. But here’s what trips people up.
Exit fees catching you by surprise. If you’re in a fixed deal, check the exit fee before you even start comparing. Some people save £200 a year on their new tariff only to discover a £150 exit fee wipes most of it out.
Switching while in debt. If you owe your current supplier money that’s been outstanding for more than 28 days, they can legally block the switch. The rule of thumb: pay the debt off first, or agree a repayment plan, before trying to switch. For debts over £500, switching is usually impossible until it’s cleared.
Erroneous transfers. Rare, but it happens. You get a welcome letter from a supplier you didn’t sign up to, or your account with your current supplier gets closed by mistake. Contact the new supplier immediately and tell them it’s an erroneous transfer. They’re required to sort it.
Silent tariff end dates. Fixed deals don’t renew themselves. They end, you get moved to the standard variable rate (the price cap), and your bills jump. Set a calendar reminder when you sign up. Don’t trust your supplier to warn you in time.
Comparison sites only showing partner deals. Stick to Ofgem-accredited sites if you want the full market. The Ofgem switching guidance is a good neutral starting point.
Quotes based on estimated usage. If the comparison site guessed your usage rather than using your real kWh figures, the “savings” it shows you are fiction. Always use your actual numbers.
What if something goes wrong?
The switching process is pretty well regulated, but things do occasionally go sideways.
If you have a problem (a delayed switch, a wrong bill, an erroneous transfer, anything else), the process is:
- Complain to the supplier first. All suppliers have a formal complaints process. Put it in writing. Keep records. Give them a reasonable chance to fix it.
- Escalate to the Energy Ombudsman after eight weeks, or sooner if the supplier gives you a deadlock letter (a letter saying they can’t resolve it). The Ombudsman is free to use and their decisions are binding on the supplier.
- Citizens Advice is the consumer support body for energy issues and can help you through the process at any stage, especially if you’re not sure whether your complaint is reasonable or how to word it.
Most switches go fine. When they don’t, you have rights, and the compensation framework is reasonably robust. Use it.
Special cases
Not everyone’s a standard dual-fuel Direct Debit customer. Here’s the stuff that trips up everyone else.
Prepayment meters
You can still switch, but the process is slightly different and the tariff range is narrower. Some suppliers only accept prepayment customers on specific prepay tariffs. You can also, in some cases, switch from a prepayment meter to a credit meter when you switch supplier, which usually unlocks cheaper deals. Worth asking about. You’ll likely face a credit check if you do.
Renters
If you pay the energy bill directly, you’re allowed to switch, full stop. Your landlord can’t stop you. If the bill is in the landlord’s name and they pass the cost through your rent, they control the tariff and you can’t switch. Check your tenancy agreement for any clauses about which supplier you must use. They’re mostly unenforceable, but worth knowing. When you move out, you should take a final meter reading and notify the supplier.
Economy 7 customers
Economy 7 uses two meters (or one with two registers) to charge a cheaper rate at night. If you switch supplier, your Economy 7 setup usually stays in place, but not every supplier offers Economy 7 tariffs, and some only offer them with a smart meter upgrade. Double-check before you commit.
Smart meter complications
If you have a first-generation smart meter (SMETS1), it might go “dumb” when you switch, meaning it stops sending automatic readings and reverts to a traditional meter until your new supplier upgrades it. The network that supports SMETS1 is being brought onto the central DCC system, which should eventually fix this, but it’s still a known issue in 2026. SMETS2 meters are fully portable across suppliers.
Debt over £500
If you owe your current supplier more than £500, you almost certainly can’t switch until it’s paid off or there’s a formal repayment plan. Ofgem has been consulting on a Debt Relief Scheme that might help some households on means-tested benefits, but the mainstream rule for now is: debt blocks switching.
FAQ
How long does it take to switch energy supplier? Most switches now complete within five working days under the Energy Switch Guarantee, though you still have 14 days to change your mind afterwards.
Will my supply be cut off during the switch? No. Your gas and electricity keep flowing the whole time. The only thing that changes is who bills you.
Can I switch if I’m in debt to my supplier? Usually not, if the debt is over 28 days old and more than around £500. Pay it off or set up a repayment plan first.
Do I need to tell my old supplier I’m leaving? No. Your new supplier handles all the communication. You just need to submit a final meter reading.
Can I switch if I rent? If the bill is in your name, yes. If it’s in your landlord’s name, no.
What happens if I change my mind? You’ve got 14 days from signing up to cancel without penalty. Contact the new supplier, ideally by email so you have a timestamp.
Is it worth switching if I’m on the price cap? It depends on what’s on offer and what the market’s doing. With the current volatility, that question deserves more than a one-line answer. See our separate guide: [Should I Switch Energy Supplier in 2026?]
Conclusion
If you’ve decided to switch, the process itself is genuinely straightforward. Get your current tariff name, unit rate, standing charge, and annual kWh usage from your latest bill. Run those through an Ofgem-accredited comparison site. Check the small print on any deal you’re considering, especially exit fees and what happens when the term ends. Apply through the new supplier. Wait five working days. Take a meter reading. Done.
If you’re on a prepayment meter, the range of deals is narrower but it’s still worth checking. You may also be eligible to switch to a credit meter, which opens up the wider market.
If you rent and the bill is in your name, you have the same switching rights as anyone else. If it’s in the landlord’s name, it isn’t really your call.
If you haven’t yet decided whether switching is the right move for you, our separate guide [Should I Switch Energy Supplier in 2026?] goes through the current state of the market and how to think about it. For the broader picture on cutting your bills, see our [The 2026 Master Guide: How to Actually Slash Your Energy Bills]. And if you’re not convinced switching alone will solve your problem, [Why Are My Energy Bills So High?] digs into the other factors.
Tariff availability, exit fees, and the price cap itself change every three months, sometimes faster. Whatever you read here about specific numbers is accurate for April 2026, so double-check current figures before committing. The mechanics themselves, though, are stable. Once you’ve decided to switch, this is how you do
