£1,723 in October, £1,878 by January. Fix Your Energy Tariff Now — the Certainty Costs You Nothing.

The Ofgem price cap resets every three months, on 1 January, 1 April, 1 July and 1 October. What was a forecast last week is now settled:

Period	Cap (new TDCV)	Status
Apr–Jun 2026	£1,477	past
Jul–Sep 2026	£1,663	in effect
Oct–Dec 2026	£1,723	confirmed 26 August
Jan–Mar 2027	~£1,878	forecast

The 4% headline understates how fast this has moved. Six weeks ago October was pencilled at £1,700. Wholesale gas — 61% higher over the past three months than late 2025 — pushed it to £1,723, and the forecasters have already shifted their attention to January.

One accounting note so you can compare like with like. Ofgem lowered its assumed "typical" usage in July to 9,500 kWh of gas and 2,500 kWh of electricity a year. On the old, higher usage assumption the October figure would have been £1,940.69. Either way the direction is identical: up. The typical household pays £350 a year more than it did in 2024, and the combined cap is the highest since July 2023. The driver is the Iran conflict feeding wholesale gas prices, which shows no sign of a cheap resolution.

For most of the energy crisis the trade-off was simple: ride the variable cap and take the risk, or pay a premium for a fixed deal and buy certainty. That premium has collapsed — and then gone negative.

A 12-month fix is available from roughly £1,620 a year. The confirmed October cap is £1,723. The January forecast is £1,878.

Break it down monthly. A fix at £1,620 is £135 a month. The October cap is £143.58 a month. The forecast January cap is £156.50 a month. Fix now and you never see £156.50.

Do the full-year arithmetic. A fix at £1,620 locks you £103 a year below the October cap. If January's forecast lands, that same fix is £258 a year cheaper through the months your boiler actually runs. The insurance premium you used to pay for certainty has not merely fallen to zero. You are being paid to take it.

That is the anomaly worth acting on. Markets rarely hand you certainty at a negative price — and when they do, the offer does not stay on the table long. It did not in May, when the best fixed deals vanished within days of a single forecast.

Staying on the cap means absorbing every quarterly reset. Ofgem caps unit rates and standing charges, not your total bill — and it re-prices every three months, passing wholesale costs through with a lag.

Ride the cap and you are betting January's forecast is wrong. Fix and you are betting it is roughly right, or worse. One of those bets is already half-won: the October rise is confirmed, not predicted.

There is also a softer cost the spreadsheet misses. Twenty-two million households in England, Wales and Scotland sit on cap-linked variable tariffs and redo their budgets every quarter. A fix ends that cycle. For a family on a tight income, knowing the largest essential bill is £135 a month, every month, until autumn 2027 is a budgeting tool — not a luxury.

Two smaller costs compound the same point. If you pay by standard credit rather than Direct Debit, the cap costs you £130–£140 a year more — and that gap persists whatever the quarterly reset does. And if you leave the decision until January, you have already paid the higher October and January caps before any new fix you sign can start. Waiting is not free; it is the most expensive option on the table. For the wider picture on how this fits your household budget, our savings hub is the place to start.

The case against fixing is honest and worth stating. Fixed deals carry exit fees of £25–£75 per fuel. Analysts have been wrong before. And a political intervention — a social tariff, or more levies moved into general taxation — could pull the variable cap down.

Each fades against what is now confirmed.

Exit fees matter if you might want to leave. But £50 of exit fees against a £258 winter saving is not a reason to stay variable.

"The analysts have been wrong" was a stronger argument when the rises were forecasts. The October rise is now a fact, announced by Ofgem. January is still a forecast — but it points the same direction as the confirmed number, and it is built on the same gas forwards. We made this case in August when the figures were still estimates — £1,663 today, £1,732 in October. Confirmation has only strengthened it.

The political bet is real but slow. Energy UK wants a discounted social tariff funded by taxation, and debt charities support it. That is a Budget question, not an October one — and it is a bet on a Chancellor, not on the market. The market has already told you where it is going.

The last time the fix-or-cap question came up in earnest, the honest answer was a coin toss. The July forecast was flat, fixed deals sat at a genuine premium, and Cornwall Insight's summer 2025 overshoot was still fresh. Either choice was defensible.

October changes the shape of the decision in three ways.

First, the rise is no longer a forecast. It is a published number, announced by the regulator, with a start date. You are no longer paying to insure against a prediction.

Second, the fixed deal is below the cap rather than above it. In May, locking in meant paying £50–£80 a year more than the variable cap for the certainty. Today it means paying £100 a year less. The sign has flipped.

Third, the next reset lands at the peak of winter. January is the quarter when a 9% rise bites hardest, because that is when your boiler runs for hours a day. A fix signed now spans that quarter at a price you already know.

None of this requires you to forecast gas markets. It only requires you to read the numbers Ofgem published on 26 August and act before suppliers reprice.

Fixed deals repriced upward within days of past announcements, and 26 August will be no different. If you are going to act, do it this week.

Three steps:

1. Find your tariff. Your bill tells you whether you are on a standard variable tariff or already fixed. Around 35% of households — 11 million — are already on fixes and are unaffected this October.
2. Compare a 12-month fix against £1,723. A genuine quote at £1,620 or below beats the confirmed cap today and the forecast January cap by a wide margin. Use a whole-market comparison site, not your supplier's own offer, and use MoneyHelper's energy advice to check the switching process.
3. Check the exit fees before you sign. £25–£75 per fuel is normal. Make sure the saving is bigger than the fee — it will be, against a £258 winter gap.

Pay by Direct Debit if you can: standard credit costs £130–£140 a year more. And claim the support you are entitled to regardless of tariff — the £150 Warm Home Discount and the means-tested Winter Fuel Payment. Our guide to energy grants runs through everything available, and our Winter Fuel Payment explainer covers the means-test in detail.

For the mechanics of switching and the full unit-rate changes, our Energy Bills Guide has the detail.