On 30 September Cornwall Insight forecast the energy price cap for 1 January to 31 March 2027 at £1,999 a year for a typical dual-fuel household paying by Direct Debit. That is 16%, or £276, above the £1,723 cap that took effect today. Cornwall calls it “the biggest price cap rise we've seen in four years”, and it would be the highest cap level since March 2023.
It is lower than the forecasts doing the rounds a week ago. On 24 September the supplier forecasts averaged about £2,120, roughly 23% up. All three suppliers have since trimmed theirs, and the latest now sit between £2,065 and £2,115.
In short
January is still almost certain to rise, and by a lot. The forecasts now range from £1,999 to £2,115, so we're using about £2,060 (+20%) as the middle figure across the site. That is about £340 a year, or £28 a month, more than October for a typical home.
The latest forecasts
All figures use Ofgem's current typical household of 2,500 kWh electricity and 9,500 kWh gas a year, so they compare directly with October's £1,723. Cornwall's forecast splits as £959 electricity and £1,040 gas, with unit rates of about 30.3p/kWh and 9.8p/kWh.
Why it's still a big rise
Wholesale gas is still well above where it was in the summer because of the conflict in the Middle East, and gas sets the price of much of Britain's electricity too. Ofgem sets the January cap from prices over an assessment window running from mid-August to mid-November. Cornwall says that window is now nearly halfway through and the September price rises are already locked in, so a January increase is “all but certain”. What happens to gas over the next six weeks will decide where in the range it lands.
Ofgem will confirm the real figure by 25 November, and it takes effect on 1 January. Electricity VAT is already at 0% in October's £1,723 and stays there until 31 March, so it gives no extra help in January.
What it could mean for your bill
A percentage rise in the cap lands on most bills at roughly the same percentage. Here's the extra cost at an annual rate, depending on what you pay now:
For your own usage, the savings calculator applies the January forecast to your bill and puts it next to today's fixed rate.
Does it change whether to fix?
Not much. A lower forecast narrows the gap but doesn't close it. Octopus's 12M Fixed averaged about £1,817 a year nationally for a typical household when we last checked. That's around £94 more than October's cap, but about £240 less than the £2,060 midpoint, and still about £180 less than Cornwall's £1,999.
- Fix prices move with the market. The same wholesale prices that set the January cap also set new fixes, so fixes may get a little cheaper if forecasts keep falling, and dearer if they turn up again.
- Exit fees are the cost of changing your mind. Octopus charges £50 per fuel to leave its 12-month fix early (£75 on the 18-month). No supplier can charge one in the last 49 days of a fix.
If you'd rather wait, you can switch to Flexible Octopus now. It follows the cap, has no exit fee, and gets you the £50 referral credit while you decide whether to fix. Our guide to fixing or staying variable works through it in detail.
Every forecast goes on our price cap predictions tracker as it lands, and our 25 September report covers the earlier, higher round of forecasts.
Sources: Cornwall Insight, MoneySavingExpert — price cap predictions, Octopus Energy product data and Ofgem. Figures last checked 1 October 2026.
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