Business energy has fewer safety nets than household energy, so the dates matter more. There's no cooling-off period, so check terms before you agree. Start your renewal 4 to 6 months before the end date. A microbusiness's notice on a rolling contract can be no more than 30 days, and the supplier must take reasonable steps to acknowledge it within 5 working days. Microbusinesses can't be back-billed for energy used more than 12 months ago. Complaints can go to the Energy Ombudsman after 8 weeks. Rules are as of 21 October 2026.
This is general information, not legal or financial advice.
Many of these protections apply only to microbusinesses: fewer than 10 employees and turnover or balance sheet of no more than £2 million, or use of no more than 100,000 kWh of electricity or 293,000 kWh of gas a year. See are you a microbusiness? for the full test.
Which dates matter when you agree a contract?
| What | Time limit | Who it covers |
|---|---|---|
| Cooling-off | None, even on a recorded phone call | All businesses |
| Written terms after a phone agreement | Within one working day | Microbusinesses |
| Rollover (evergreen) period | Can't be longer than 12 months | Microbusinesses |
Read the full written terms before you say yes. Our guide to verbal contracts explains why a recorded "yes" can be binding.
Which dates matter at renewal?
| When | What happens | Who it covers |
|---|---|---|
| 6 to 4 months before the end date | Find your end date, last notice date and 12 months of kWh; start comparing | Everyone (good practice) |
| About 3 months before | Your supplier should contact you with your options | Microbusinesses |
| Around 60 days before | Renewal letter with current prices, new prices and annual use | Microbusinesses |
| Notice to leave | Any time before the last termination date; on a rolling contract, no more than 30 days (contracts that started before 30 April 2015 can still require up to 90 days) | Microbusinesses |
| After you give notice | Supplier takes reasonable steps to acknowledge it within 5 working days | Microbusinesses |
Larger businesses should read their contract: notice periods and rollover terms can be longer. Use our contract notice calculator to work out your dates, and see the renewal checklist.
Which dates matter for bills, debt and moving?
| What | Time limit | Who it covers |
|---|---|---|
| Back-billing | No charge for energy used more than 12 months before the bill, unless you stopped accurate billing | Microbusinesses |
| Disconnection for debt | At least 7 days' written notice, which can't start until 28 days after a written demand | All businesses |
| Warrant to enter | Lasts up to 28 days from the date it's granted | All businesses |
| Breathing Space (debt respite) | Stops most enforcement, interest and charges for 60 days | Eligible business owners (via Business Debtline) |
| Change of tenancy documents | Supplier reviews them within 10 working days | All businesses |
Business Debtline notes that contracts often say only 7 days' notice is needed, so don't assume you have longer. On a deemed contract, a supplier can't stop you switching because of debt. See what suppliers can and can't do about debt and the back-billing rules.
How long do you have to complain?
- Complain to the supplier or broker. Write down the date: the 8 weeks start then.
- Wait up to 8 weeks. If it isn't fixed, or you get a deadlock (final response) letter sooner, eligible micro and small businesses can go to the free Energy Ombudsman.
- Escalate within 12 months of a deadlock letter.
- During the case, both sides usually send evidence within 14 days. If you accept the decision, the supplier has 28 days to do what it's told.
Small businesses (fewer than 50 employees and turnover up to £6.5 million or balance sheet up to £5 million, or up to 200,000 kWh of electricity or 500,000 kWh of gas a year) have been able to use the Ombudsman since 19 December 2024. In June 2026 the government said the wait will drop from 8 weeks to 6 weeks; no start date has been set, so 8 weeks still applies. Full steps are in the bill dispute guide.
Worked examples: what dates should you put in your diary?
Fixed contract ending 31 March 2027 (microbusiness). Start comparing in October or November 2026. Expect contact from your supplier around January 2027 and a renewal letter around late January. Give written notice before the last termination date shown on your bill, and keep proof. If you're on a rolling contract instead, 30 days' notice means telling the supplier by 1 March 2027 to leave on 31 March.
Complaint made on 21 October 2026. Eight weeks later is 16 December 2026. If it isn't fixed by then, you can take it to the Ombudsman without a deadlock letter.
Catch-up bill dated 21 October 2026 (microbusiness). Charges for energy used before 21 October 2025 should normally come off.
What to do next
- Find your contract end date and last notice date on your bill (microbusiness bills must show both).
- Diary reminders at 6 months, 3 months and 2 weeks before the notice date.
- Give notice in writing and keep proof; chase if it isn't acknowledged within 5 working days.
- Never agree a contract on the spot: there's no cooling-off period.
- Check any catch-up bill for energy used more than 12 months ago.
- When you complain, write down the date and diary 8 weeks.
- Check what you should be paying with our free estimator, and look up any term in the business energy glossary.
BusinessEnergy.ai is not a supplier or broker. Our estimator gives an estimate, not a quote.