What happens if I miss my termination window?
You will normally be moved onto a rollover contract or out-of-contract rates, both of which are considerably more expensive than a negotiated deal — out-of-contract rates commonly run 35–45p per kWh. Serve notice immediately anyway: it starts the clock and caps how long you are stuck. If you are a micro business the maximum notice a supplier can require is 30 days.
Last reviewed 2 September 2026 by Utilities Made Simple · independent, whole-of-market, supplier-paid — how we are paid
The two things that can happen
A rollover. Some contracts allow the supplier to extend you onto a further fixed term, usually at a rate you did not negotiate. Out-of-contract or deemed rates. More commonly you drop onto the supplier's default variable rate, which carries no cap protection and is the most expensive electricity in Britain — see deemed and out-of-contract rates.
Do this today, in this order
- Serve notice in writing. Email the supplier, keep the sent copy. Ofgem requires suppliers to take all reasonable steps to acknowledge a termination notice within five working days, so chase if nothing arrives.
- Ask for your contract end date in writing and what rate you are on right now. Both should be on your bill; if they are not, ask.
- Price the market before you agree anything the supplier offers over the phone while you are exposed. Renewal offers made to customers on out-of-contract rates are rarely their best.
If you are a micro business
Ofgem caps the notice period a supplier can require from a micro business at 30 days. You count as a micro business if you have ten or fewer employees and turnover or balance sheet under €2 million, or you use no more than 100,000 kWh of electricity or 293,000 kWh of gas a year. That means the worst case is usually weeks of exposure, not months — but only once notice is actually served.
The lasting fix is a diarised end date. Our contract end-date reminder puts the date in your calendar with the notice deadline attached.
Ask an energy specialist
If your question is not answered above, send it to us. A specialist answers personally, normally within one working day. No sales call, no obligation — and if the answer is "your deal is fine", that is what you will get.
Want this checked against your own bill?
Email a recent bill to info@utilitiesms.co.uk and a specialist will check your rates, VAT, levies and contract end date against the live market — free, usually the same working day. If your deal is already good, we will tell you to keep it.