📍Where Things Stand Right Now
Two things land within weeks of each other. Ofgem confirms the October–December price cap by 26 August 2026, and on 1 October VAT on domestic electricity falls from 5% to 0% until 31 March 2027. Both change the number on your bill, and they pull in opposite directions.
The current cap sits at £1,663 a year for a typical dual-fuel household paying by direct debit. Cornwall Insight — the forecaster most often quoted on this — currently expects around £1,700 for October, a rise of roughly 2%. That already accounts for the VAT cut, without which the forecast would have been far higher; wholesale gas has firmed up over the summer and largely offset the tax relief.
Why this year's case for fixing is weaker than usual
People fix when they fear a large jump. A forecast 2% rise is not that — it's roughly £3 a month on a typical bill, and it's within the margin by which forecasts routinely miss. Fixing to avoid £3 a month, at the cost of twelve months of flexibility, is a trade most households would not knowingly make. That calculus changes if the 26 August announcement comes in materially above expectations, which is exactly why waiting a couple of weeks costs you nothing.
🔒What Fixing Actually Does — and What It Doesn't
A fixed tariff locks your unit rates and standing charges for a set period, usually twelve months. That is the entire product. Everything else people assume about fixing is either a bonus or a misunderstanding:
- It does not fix your bill. This is the one that causes arguments with suppliers every winter. Your rates are fixed; your bill still rises when you use more energy, and you use far more in January than in July.
- It does not protect you from the price cap rising — because the cap never applied to you anyway. The cap governs default variable tariffs. Once you fix, Ofgem's quarterly announcements are simply news.
- It is not a bet you can only win. If the cap falls below your fixed rate, you keep paying the higher rate until the fix ends. Certainty cuts both ways, and that is the price of it.
- It does not stop VAT changes reaching you. Tax is applied on top of your tariff, so the October cut lands for fixed customers too. More on that below.
Put simply: fixing converts an unknown into a known. Whether that's worth paying for depends on how badly an unknown would hurt you — a genuine question about your finances, not a prediction about the gas market.
⚖️The Three Options Compared
Most coverage frames this as fixed versus variable. That's a false binary — there are three genuinely different shapes of tariff, and the third one is the one most people never consider:
The row that changes the decision is the second-to-last one. Exit fees are what make fixing a commitment rather than a preference — and with a supplier that charges none, a fix stops being a lock and becomes a floor you can walk away from. That's a materially different product sold under the same name.
Worth knowing on the middle column too: a standard variable tariff doesn't have to sit at the cap. The cap is a ceiling, and Octopus prices Flexible Octopus a little below it — so "staying variable" with a cheap supplier isn't the same decision as staying variable with an expensive one.
🧾The VAT Complication Nobody Mentions
A lot of people fixing this summer assume they'll miss out on the 0% VAT on electricity arriving on 1 October. They won't. VAT is a tax on the supply of energy, not a component of your tariff — so when the rate changes, it changes for everyone. Your fixed unit rate excluding VAT stays locked; the VAT-inclusive amount you actually hand over for electricity falls.
Where it does get confusing is comparison. Fixed deals are typically advertised VAT-inclusive, so a quote given today for a tariff starting in September carries 5% VAT on electricity that will disappear a few weeks later. That makes an August quote look worse against an October one than it really is.
The date that should be in your diary: 1 April 2027
The electricity VAT cut is temporary and currently reverts to 5% on 1 April 2027. A twelve-month fix taken now runs past that date — so your electricity costs will step up partway through the fix through no fault of your supplier, and the market you return to at the end won't be the one you left. If it's extended in a future Budget, all the better; plan on the current law rather than the hoped-for one.
One more thing to hold loosely: forecasters have flagged that a further cut — taking VAT to zero on gas as well — could be announced in a future Budget, worth roughly a further £80 a year. That is speculation about a decision nobody has taken, and it is not a reason to delay a decision you'd otherwise make.
🔍How to Compare a Fix Properly
Comparison sites lead with an annual figure, and this year that figure is unusually treacherous. On 1 July 2026 Ofgem changed its assumption about how much energy a typical household uses — down from 2,700 to 2,500 kWh of electricity and from 11,500 to 9,500 kWh of gas. The same cap is now quoted as £1,663 where it would previously have been called £1,862. Nothing about the price changed; only the yardstick did.
Marketing material written before the change may still use the old basis. Compare two annual figures built on different assumptions and you will reach a confidently wrong conclusion. So compare these instead:
The four numbers that matter
- Electricity unit rate (p/kWh) — against today's cap rate of 26.11p
- Gas unit rate (p/kWh) — against today's cap rate of 7.33p
- Both standing charges (p/day) — against 57.19p electricity and 29.04p gas
- The exit fee, per fuel — the number that decides whether a mistake is recoverable
Then express the fix as a percentage above or below the cap. That number is comparable across suppliers, survives changes to Ofgem's consumption assumptions, and tells you exactly what you're paying for certainty.
Then apply it to your own annual kWh, which is on your annual statement or in your supplier's app. A fix with a low unit rate and a high standing charge suits heavy users; the reverse suits light ones. The "typical household" in the adverts is a statistical artefact, and it's probably not you — the same logic that governs low standing charge tariffs.
👥Who Should Fix — and Who Shouldn't
If an unexpected £15 a month in January would mean something else goes unpaid, the value of knowing your rate exceeds the expected saving from staying flexible. That's a legitimate reason to fix even when the forecast says prices are flat, and it doesn't require you to have a view on wholesale gas. Landlords budgeting for a void period and anyone on a rigid monthly plan fall in the same category.
With the October cap forecast around 2% higher and no exit fees on a variable tariff, staying put costs you very little optionality and keeps every door open. A cheap supplier's standard variable tariff priced below the cap is a perfectly respectable default — the mistake is not being variable, it's being variable with an expensive supplier who is charging you the full cap because you've never looked.
If you can move consumption — charging overnight, running the washing machine at 2pm, heating water when the wind is blowing — a tracker or half-hourly tariff will usually beat both a fix and the cap by a wider margin than the fix-versus-variable question is worth arguing about. With electricity VAT at 0% from October and gas staying at 5%, electricity-heavy households gain a second tailwind here.
Roughly speaking, every scenario above beats staying on a legacy default tariff with a supplier you last thought about years ago. Whatever Ofgem announces on 26 August applies to that tariff in full, and no forecast changes the fact that you're paying the ceiling. If you take one action this month, make it this one.
🚪Why Exit Fees Decide This More Than Rates Do
Here's the part that gets least attention and matters most. The risk in fixing isn't that you pay slightly over the odds — it's that you're stuck paying slightly over the odds for a year while the market moves without you. Exit fees are what convert a small pricing error into a twelve-month one.
Typical exit fees run £25 to £150 per fuel, so leaving a dual-fuel fix early can cost up to around £300. That is usually more than the difference you'd be escaping, which is precisely the point of the charge: it makes the rational move impossible.
Octopus charges no exit fees on any domestic tariff — fixed, variable, Tracker, Agile, Go, Cosy, Flux, all of them. Practically, that changes the decision more than a penny or two on the unit rate:
- You can fix now and leave later if the October announcement makes the fix look wrong, without paying for the privilege.
- You can switch now and decide later — move to a variable tariff today, take the £50 credit, and choose after 26 August with the actual number in front of you.
- You can change as your life changes — an EV or a heat pump arriving mid-year should move you onto a smart tariff, and nothing should stand in the way of that.
A fix you can leave for free is a price floor rather than a cage. That's the version of this product worth having, and it's why the exit fee line deserves as much of your attention as the unit rate.
✅Verdict — Decide About Your Budget, Not the Gas Market
Verdict: With October forecast around 2% higher, fixing is a preference this year — not a rescue.
The cap sits at £1,663 and is expected near £1,700 from October, confirmed by 26 August. That's roughly £3 a month — too small to justify a twelve-month commitment on its own. Fix if a winter surprise would genuinely hurt, because certainty has real value and you don't need a market view to buy it. Stay flexible if you can absorb a few percent, and go tracker or smart if you can shift when you use energy. Check the exit fee before the unit rate, remember the 0% electricity VAT reaches fixed customers too and reverts on 1 April 2027 — and don't let indecision leave you on a default tariff, which is the one choice that loses whatever happens.
Because Octopus charges no exit fees on any tariff, switching now doesn't commit you to an answer — you can move today, take the £50 referral credit, and pick your tariff properly once Ofgem publishes on 26 August. Octopus supplies 7.3 million UK households, has been Which? Recommended for 9 consecutive years and holds a 4.8/5 Trustpilot rating from 800,000+ reviews. Read our Octopus Fixed review if you've decided to lock in, or compare every Octopus tariff if you haven't.