Most household energy rights in Great Britain come with a clock. You have 14 days to cancel a new deal, a switch should take 5 working days, there's no exit fee in the last 49 days of a fix, your final bill is due within 6 weeks, suppliers usually can't charge for energy used more than 12 months ago, and you can go to the Energy Ombudsman after 8 weeks. This page puts them all in one place, so you know when to act and when you're owed money.
Which time limits apply when you switch?
| What | Time limit | What happens if it's missed |
|---|---|---|
| Cooling-off on a new contract | 14 days, starting the day after you agree | You can cancel without a fee within this time |
| How long a switch takes | 5 working days, unless you ask to wait | You should get £40 automatically, within 10 working days |
| If the switch went through in the cooling-off period | 15 working days to agree a new contract, go back on equivalent terms, or switch again | Ask the supplier to put it right, then complain |
| Exit fees on a fixed deal | None with 49 days or less left | With 50 days or more left, a fee may apply |
| Switching with debt (credit meter) | Usually fine if your last bill was sent less than 28 days ago | An unpaid bill older than 28 days can block the switch |
The 5-working-day clock starts the same day if you agree before 5pm on a weekday, or the next working day otherwise. See our switching checklist for the full steps.
Which time limits apply to bills and refunds?
| What | Time limit | What you're owed if it's missed |
|---|---|---|
| Final bill after you switch or move | 6 weeks | £40, paid automatically |
| Refund of credit after the final bill | 10 working days | Another £40 |
| Back-billing | Usually no charge for energy used more than 12 months before the bill | Ask for the older charges to be removed |
| Smart meter fault reported | Supplier has 5 working days to check whether it's working | Complain if it doesn't |
| Guaranteed Standards payment | Paid within 10 working days | Another £40 for each step not done |
| Cold Weather Payment after a cold spell | Within 14 working days | Contact the Pension Service, Jobcentre Plus or your Universal Credit journal |
Back-billing has exceptions: it doesn't apply if you blocked accurate billing, ignored correct bills, or took energy illegally. Read the back-billing guide for the letter to send.
How long do you have to complain?
- Complain to the supplier first. Write down the date: the clock starts then.
- Wait up to 8 weeks. If it isn't fixed after 8 weeks, or the supplier sends a "deadlock" (final response) letter sooner, you can go to the free Energy Ombudsman.
- Don't leave it too long. If you get a deadlock letter, you must take the complaint to the Ombudsman within 12 months of receiving it.
In June 2026 the government said the wait will drop from 8 weeks to 6 weeks, with the Ombudsman aiming to resolve cases within 4 weeks. No start date has been set, so 8 weeks still applies for now.
Worked examples: what dates should you put in your diary?
Fixed deal ending 31 March 2027. Count back 49 days: from 10 February 2027 you can switch with no exit fee. That's also a good time to compare a year's cost on your own kWh.
Complaint made on 21 October 2026. Eight weeks later is 16 December 2026. If it isn't fixed by then, you can go to the Ombudsman, even without a deadlock letter.
Switched supplier on 1 December 2026. Your old supplier's final bill is due by 12 January 2027. If you're in credit and the bill arrives that day, the refund is due by 26 January 2027 (10 working days).
What to do next
- When you agree a new deal, diary the end of the 14-day cooling-off period.
- If you're on a fixed deal, diary the date 49 days before it ends.
- After a switch or move, diary 6 weeks for the final bill and 10 working days after that for any credit.
- When you complain, write down the date and diary 8 weeks.
- Keep every deadlock letter: you have 12 months to use it.
- Check a bill for energy used more than 12 months ago before you pay it.
- Check what your bill should be with our free estimator, and look up any term in the energy bill glossary.
Related guides: Is your Direct Debit too high?, estimated bills, fixed or variable and your energy rights.
This is general information, not legal advice. Figures are for Great Britain; Northern Ireland has separate rules. EnergyQuote.ai is not a supplier, broker or comparison site, and our estimator gives an estimate, not a quote.
Sources
- Citizens Advice: Switch energy supplier or tariff
- Citizens Advice: Switching if you owe your energy supplier money
- Citizens Advice: Claim back credit from your energy supplier
- Ofgem: What to do if you get a back bill
- Citizens Advice: If you're having problems with your smart meter
- Energy Ombudsman: Frequently asked questions
- Energy Ombudsman: Fairer, faster redress for energy consumers (18 Jun 2026)
- GOV.UK: Cold Weather Payment, when you'll get paid