Ofgem will reveal the next energy price cap on 25 November 2026 – and suppliers still owe customers at least 30 days’ notice of any price change
Key points
- Ofgem will announce the default tariff price cap for 1 January to 31 March 2027 on 25 November 2026, roughly five weeks before it takes effect.
- Under Standard Licence Condition 23, energy suppliers in Great Britain must give domestic customers at least 30 days’ advance notice before a price rise or a contract change that leaves them significantly worse off.
- For the current quarter (1 October to 31 December 2026), a typical household on a default tariff paying by direct debit pays 26.32p per kWh for electricity and 7.97p per kWh for gas, plus daily standing charges – a 4% rise on the previous quarter.
Anyone on a standard variable or default energy tariff in Great Britain will find out the new price for January 2027 on 25 November. Suppliers then have a legal duty to tell customers about the change with enough notice before it bites.
Unlike Germany, where each supplier sets its own price and must announce a rise six weeks in advance under the StromGVV and GasGVV, Great Britain runs a national price cap: Ofgem itself calculates the maximum unit rate every three months, and suppliers’ standard variable tariffs move with it. The notice duty sits on top of that cap – it governs how suppliers communicate the change, not whether it happens.
Why 25 November matters
Ofgem sets the default tariff cap – often called the energy price cap – four times a year, for the quarters starting 1 January, 1 April, 1 July and 1 October. The cap limits what suppliers can charge per unit of gas and electricity and the daily standing charge for customers on a standard variable tariff; it does not cap the total bill, which still depends on how much energy a household uses. Ofgem confirmed that the next announcement, covering 1 January to 31 March 2027, falls on 25 November 2026 – about five weeks before the new rate starts.
That gap is not an accident. It gives suppliers time to update bills and websites, and it gives Ofgem’s own notice rules (see below) room to apply before the 1 January switch-over. Fixed-rate deals are unaffected by the cap change itself, but a supplier can still only move a customer off a fixed deal, or raise its price, following the same notice duty.
The 30-day notice rule
Since 2011, Ofgem’s Standard Licence Condition 23 has required every domestic gas and electricity supplier to give customers at least 30 days’ advance notice of a price increase, or of any other contract change that leaves them significantly worse off. Ofgem introduced the duty after finding that some suppliers were raising prices with little or no warning, leaving customers unable to shop around before the higher price applied.
The obligation sits alongside Ofgem’s broader Standards of Conduct, which require suppliers to communicate clearly and not put unreasonable barriers in the way of customers who want to leave. A supplier that fails to give proper notice risks enforcement action by Ofgem, separate from whatever price change it was trying to make.
What the current cap already costs
For the quarter running from 1 October to 31 December 2026, Ofgem’s published cap means a typical household on a default tariff, paying by direct debit, faces a unit rate of 26.32p per kWh for electricity plus a daily standing charge of 54.83p, and 7.97p per kWh for gas plus a daily standing charge of 29.68p – a 4% rise on the previous quarter, according to Ofgem’s own summary. Electricity bills currently carry no VAT, a temporary measure due to run until 31 March 2027; gas bills still carry 5% VAT.
Whether the January 2027 cap rises or falls again depends mainly on wholesale gas and electricity prices over the autumn, which Ofgem will only lock in with the 25 November announcement.
What the notice period means in practice
Working through the 30-day rule against the cap calendar
- 25 November 2026: Ofgem publishes the new cap level for January to March 2027.
- 1 January 2027: the new unit rates and standing charges take effect for customers on a standard variable tariff.
- Gap between announcement and effect: about five weeks – comfortably more than the 30-day minimum suppliers must give under SLC 23.
Because the cap is published before suppliers send individual notices, most customers on a default tariff see the new rate on their account well inside the legal 30-day window. The margin narrows sharply for anyone who switches supplier or tariff close to the cap announcement, since a new contract resets the notice clock for that supplier.
What you can do now
A household does not have to wait for the 25 November announcement to act. Comparing deals now, and understanding the rules that apply when switching, can avoid a scramble once the new cap is confirmed.
Checklist before 1 January 2027
- Check whether your current deal is a standard variable tariff (moves with the cap) or a fixed-rate deal (does not move with the cap, but still needs 30 days’ notice of any change).
- Read any notice letter or email from your supplier carefully: it should state the new unit rates, the standing charge and the date the change takes effect.
- Use an Ofgem-accredited comparison service before switching, and check whether a fixed deal you are leaving carries an exit fee.
- If a price rise notice looks unclear or arrives late, Ofgem’s Standards of Conduct give you grounds to complain to the supplier and, if unresolved, to the Energy Ombudsman.
None of this changes what Ofgem will actually decide on 25 November. But it means the notice, once it arrives, is a confirmation to act on rather than a surprise to react to.
Frequently asked questions
Does the 30-day notice rule mean my bill cannot rise before 30 days have passed?
Yes, for the specific price rise your supplier is notifying you about. Standard Licence Condition 23 requires at least 30 days’ advance notice before a price increase or a significantly detrimental contract change takes effect for a domestic customer.
Will the January 2027 cap definitely be higher than the current one?
That is not yet known. Ofgem only confirms the next cap level on 25 November 2026, based on wholesale energy costs and other regulated costs up to that point – this article does not predict the direction.
Does the price cap apply to fixed-rate deals too?
No. The default tariff cap applies to standard variable tariffs. Customers on a fixed-rate deal keep their agreed price until the fixed term ends, but any change their supplier proposes still needs the same 30 days’ notice.
What can I do if my supplier changes my price without proper notice?
You can complain directly to the supplier first. If the issue is not resolved, Ofgem’s rules allow you to escalate the complaint to the Energy Ombudsman, which can order compensation or a correction.
Have you already received a notice letter about your energy price for January 2027, and did it clearly explain the new rate? Share your experience in the comments.
Sources and status
- Ofgem: “Changes to energy price cap between 1 October and 31 December 2026”, accessed 8 November 2026.
- Ofgem: Guidance on notification of price increases – Standard Licence Condition 23, accessed 8 November 2026.
- Ofgem: Switch your home energy supplier, accessed 8 November 2026.
Research and data as of: 8 November 2026.
Transparency note: AI-assisted tools were used in researching, structuring and writing this article. The sources used are listed in the article. Publication takes place only after manual editorial approval. Country edition researched for Great Britain, based on an article by Net Trends on the German notice period for electricity and gas price changes; the German case does not carry over directly, so UK sources, rules and figures were researched separately. Featured image: own illustration based on a Pixabay photograph, see image credit.
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