How to Leave British Gas

Leaving British Gas is simpler than most people expect, because you don't have to contact British Gas at all. You sign up with the new supplier, the new supplier tells British Gas, and the switch happens in the background. Your gas and electricity stay on throughout, your meter stays on the wall and nobody needs to visit.

What's worth doing before you sign up is a five-minute check of your British Gas account: which tariff you're on, whether it's fixed, when it ends and whether there's an exit fee. Everything else on this page (final bill, credit refund, smart meter, Hive, HomeCare) sorts itself out or needs one small action from you.

If you haven't decided where to go yet, our Octopus vs British Gas comparison puts prices, customer service and tariffs side by side. British Gas is a big, established supplier and suits some households well; this guide is for people who have already decided to move and want to do it cleanly.

On a standard variable tariff (the one governed by the Ofgem price cap) there is no exit fee, so you can leave British Gas at any time.

On a fixed tariff, British Gas says you may be asked to pay an exit fee if you leave before the deal ends. The amount is in the terms and conditions for your specific tariff, which you can see by logging in to your British Gas online account. If you're dual fuel, check the terms for both gas and electricity.

The rule that matters most: no exit fee applies in the final 49 days of a fixed deal. This is an Ofgem requirement, and British Gas's help pages confirm it (“the final 49 days / seven weeks”). Suppliers also have to write to you before a fix ends to remind you of this window. If you're a few weeks outside it, you can sign up with a new supplier now and ask for the switch to start on a later date that falls inside the window.

If you're well outside the window, do the arithmetic rather than assuming the fee rules it out. A small fee can be outweighed by a cheaper tariff plus the £50 referral credit. For more on the trade-off, see our guide to fixing versus staying variable. For what it's worth, Octopus charges no exit fees on Flexible Octopus or on its 12-month fixed tariff, so you won't face the same question if you ever leave again.

British Gas works out your final bill from a meter reading taken on the day the switch completes. If your smart meter is sending readings, this happens automatically. If not, your new supplier will ask you for an opening reading, and that same reading closes your British Gas account.

Either way, take a dated photo of each meter on switch day. It costs nothing and settles any disagreement about estimated readings later.

British Gas says it typically takes no more than four weeks to close your account and send your final bills, and gas and electricity may arrive as separate bills. Under the industry rules, your old supplier must send the final bill within six weeks of the switch, and Citizens Advice notes you may be owed compensation if it's late.

Don't cancel your British Gas Direct Debit straight away. Leave it in place until the final bill has been paid or refunded, so British Gas can collect a last payment or send money back the same way. The same advice applies when you move house, which we cover in our moving home guide.

If you pay by Direct Debit, there's a good chance your account is in credit, especially after summer. That money is yours. Once the final bill is issued, the old supplier must refund any credit within 10 working days, and late refunds can trigger compensation.

British Gas says it refunds via your Direct Debit or into your bank account, and sends a cheque if neither is possible. If you've changed bank since setting up the Direct Debit, update your details in your British Gas account before the final bill so the refund doesn't bounce.

You don't have to wait for a switch to get excess credit back, either. Ofgem says you can contact your supplier to claim credit back at any time, though it suggests thinking about whether you'll need it for upcoming winter bills first.

Your meter doesn't belong to British Gas in any way that stops you leaving, and it doesn't get swapped when you switch. What matters is which generation it is.

SMETS2 meters, fitted in recent years, connect to the national smart meter network run by the Data Communications Company (DCC). They carry on sending readings to whichever supplier you choose.

SMETS1 meters, the first generation, used to lose their smart features when you switched. Most have since been moved onto the DCC network remotely, which lets them keep working after a switch. British Gas notes that some early smart meters may still lose some functionality when you move to another supplier. If that happens, the meter still records your usage correctly; you just submit readings yourself until the new supplier upgrades or replaces it.

Citizens Advice has an online checker to see whether your meter will stay in smart mode. Our smart meters guide explains the difference in more detail, and why a working smart meter opens up Octopus's cheaper smart tariffs.

British Gas customers often have a few extras attached to their account. Here's what happens to each.

• ✓Hive thermostat and app. Hive is made by Centrica, British Gas's parent company, but it works with any energy supplier. Your thermostat, heating schedule and app keep working after you switch. Any paid Hive subscription is a separate arrangement, so check your Hive account if you want to change it.
• ✕Hive Saver tariff. This is a British Gas energy tariff offered with a new boiler and Hive thermostat, described as a fixed rate. Like any British Gas tariff it ends when your energy moves, and because it's fixed, check its terms for an exit fee and its end date first.
• ✕PeakSave. PeakSave's cheaper electricity windows are part of British Gas electricity tariffs and need British Gas to be reading your smart meter, so they stop once your electricity moves. Octopus has its own versions, such as Saving Sessions through its free Octoplus rewards scheme.
• ?British Gas Membership (formerly Rewards). British Gas describes Membership as free and open to British Gas customers, with some perks, such as its energy prize draw, only for energy customers. If you keep another British Gas product such as HomeCare you may still qualify for some of it; check your account for what you'd keep.

On a credit meter (you get a bill or pay by Direct Debit), owing British Gas money doesn't automatically stop you leaving. Ofgem's rules let a supplier object to a switch if you've owed money for more than 28 days. If the debt is newer than that, you can switch and it's simply added to your final bill. If British Gas does object, paying down the older debt, or agreeing a plan and clearing it, lets you try again.

On a prepayment meter, Ofgem's Debt Assignment Protocol lets you switch with up to £500 of debt, provided the new supplier agrees to take it on. Each supplier decides whether to accept, so ask before you sign up. British Gas also warns prepayment customers to use up any credit on the meter before switching to the new supplier's key, card or top-up, or it could be lost.

Our prepayment meters guide covers switching on prepay in full, including moving from prepay to a credit meter once you're with Octopus.

Boiler and heating cover is the thing that keeps most British Gas customers from switching, and it needn't. British Gas says switching energy supplier doesn't affect HomeCare: your cover continues as normal unless you decide otherwise. Energy and HomeCare are separate agreements, and switching one leaves the other alone.

The things worth checking are whether your HomeCare price included any offer linked to your energy account, and your renewal date. We go through that in detail in Can you keep British Gas HomeCare if you switch energy supplier?

The full walkthrough is on our how switching works page. Octopus supplies around 7.3 million households, holds a 4.8/5 Trustpilot rating from over 800,000 reviews and has been a Which? Recommended Provider for 9 years. Our Octopus Energy review covers the weaker points as well as the strong ones.

Not sure which tariff to pick? Most people switching from a British Gas variable tariff start on Flexible Octopus, which has no exit fees, and move to a fix or a smart tariff later if it suits them. If you'd rather lock your rates now, look at Octopus 12M Fixed.

Every new energy contract comes with a 14-day cooling-off period. If you cancel within it, you won't pay an exit fee and the switch is stopped. British Gas applies the same rule to its own contracts: 14 days from the date you agree to start a new supply.

If a switch ever goes wrong, for example it takes longer than 5 working days without you asking for a later date, or you're switched by mistake, Ofgem's rules entitle you to automatic compensation from the supplier at fault.