How to Find the Cheapest Energy Supplier (Autumn 2026 Guide)

Ofgem confirms the October price cap in late August, and the fortnight around it is when suppliers release their best fixed tariffs — and when the worst switching decisions get made. People jump at the biggest number on a savings banner rather than the tariff that is cheapest for how their home uses energy.

A proper comparison takes 30–45 minutes, costs nothing, and in the current market typically saves £100–£250 a year against the cap. Below is the method, including the usage-profile trap and the details comparison sites rarely explain: exit-fee windows, credit rules and tenants' rights.

Comparison sites will happily estimate your usage from your postcode and bedroom count. Don't let them — estimates are how people land on tariffs that look cheap and aren't. Gather real numbers first:

• •A recent bill or your supplier's app — annual usage in kilowatt hours ('estimated annual consumption' for each fuel), not pounds.
• •If one fuel is missing, Ofgem's medium-household benchmarks are roughly 2,700 kWh of electricity and 11,500 kWh of gas a year.
• •Your current tariff name, end date and exit fee, listed on the bill or under tariff details in the app.
• •Your postcode and payment method; monthly direct debit is almost always priced cheapest.
• •Time: 30–45 minutes to compare, five to apply. Cost: nothing — the new supplier runs the whole switch.

Scam activity spikes around every cap change. Nobody legitimate needs your bank details to 'check whether you qualify' for anything.

• •Stick to comparison sites accredited under Ofgem's Confidence Code — the logo sits in the footer and obliges the site to rank tariffs fairly.
• •No genuine supplier cold-calls demanding card details to 'hold' a deal. Hang up and call back on a number you found yourself.
• •Ignore social-media adverts promising government energy rebates — the same credential-harvesting scam returns every autumn.
• •Never pay an upfront switching fee — sites earn commission from suppliers, not you — and check any unfamiliar supplier holds a licence on Ofgem's published list.

With real kWh figures to hand, the process is quick. The discipline is in steps 2, 5 and 6 — the ones most people skip.

• •1. Enter your postcode and actual annual kWh on a first comparison site, overriding any estimate it offers.
• •2. Switch the results to whole-of-market, not 'tariffs we can switch you today' — the default view hides deals that pay no commission.
• •3. Repeat on a second accredited site; exclusives differ, and the duplication regularly finds another £40–£60 a year.
• •4. For each shortlisted tariff, note four numbers: both unit rates, both standing charges, and the exit fee per fuel.
• •5. Judge tariffs against your current unit rates, not the 'projected saving' banner, which assumes the cap rises as forecast and flatters the figure.
• •6. Check the credit rules: how the direct debit is set and reviewed, and how to reclaim a building balance — suppliers must set direct debits fairly and refund credit promptly on request.
• •7. Apply through the site or direct with the supplier — the price is the same either way.
• •8. The switch completes within five working days under the Energy Switch Guarantee, with a 14-day cooling-off period to cancel penalty-free.
• •9. Photograph your meters on switch day and submit the readings so neither side estimates the handover.
• •10. Your old supplier must send a final bill within six weeks and refund credit within ten working days of it — £30 compensation if they miss either.

Two tariffs shaped like last autumn's crop show the trap. Tariff A: electricity at 24.5p per kWh with a 62p daily standing charge. Tariff B: 27p per kWh with a 41p standing charge. Gas is stripped out to keep the sums visible; the same logic applies.

For a one-bed flat using 1,800 kWh a year, Tariff A costs £441 in units plus £226 in standing charges — £667. Tariff B costs £486 plus £150 — £636. The 'expensive' unit rate wins by £31. For a four-bed house using 4,300 kWh, A totals £1,280 against B's £1,311, and the answer flips. Same tariffs, opposite verdicts, purely down to usage.

The rule of thumb: low users should hunt down the standing charge; high users — electrically heated flats, heat-pump homes, EV chargers — should chase the unit rate. This is why genuine kWh figures matter more than any other step. Bear the shape of the latest rise in mind as well: October's increase is almost entirely a gas rise, which changes where switching can actually help.

A fix earns its keep when it prices below the current cap and you would rather have certainty than gamble on the January announcement. Our rule of thumb: a fix within a few percent of the cap with no exit fee is rarely a bad decision; one 10% above only makes sense if forecasts point sharply up. Ofgem bans exit fees in the final 49 days of any fixed term, so you can line up the next deal early; mid-fix exit fees of £25–£75 per fuel often pay back within months anyway. Whether fixing beats the default rate at all is its own question — our guide to fixing your tariff versus staying on the cap works the numbers.

Remember, too, that switching changes the price per kilowatt hour, not how many you burn. Draught-proofing and a properly programmed thermostat routinely trim usage by 10% — a permanent saving that outlasts any tariff. Our home energy efficiency checklist ranks the rest of the jobs by payback.

Most switches are invisible — same wires, same pipes, new biller. When one does snag, the fixes are well defined:

• •Switch stuck past five working days: chase the new supplier, who owns the process; delays they cause trigger £30 compensation under Ofgem's guaranteed standards.
• •Switched without consent (an erroneous transfer): call your real supplier — the two must restore your original tariff, and £30 compensation applies.
• •Credit still unpaid ten working days after the final bill: the refund is late — claim it plus the automatic £30.
• •Debt owed for under 28 days moves to your final bill and cannot block a switch; prepayment customers can switch with up to £500 of debt per fuel under the Debt Assignment Protocol.
• •Renting: if your name is on the bill you have the right to switch whatever the tenancy says — a landlord may require the original supplier restored when you leave, but cannot veto the switch. Landlords who re-bill energy are capped at cost under the maximum resale price rules.

If a dispute stalls, the Citizens Advice consumer service (0808 223 1133) is the free first stop; after eight weeks, or with a deadlock letter, the Energy Ombudsman rules at no cost. If the real problem is affording the bill, talk to your supplier before autumn — they must offer a payment plan you can afford — and anyone elderly, disabled or medically dependent on power belongs on the Priority Services Register.

Park homes and heat networks are the exception: residents usually cannot switch, though heat networks now fall under Ofgem's remit. For jobs that cut the bill whoever supplies it, from loft insulation to bleeding sluggish radiators, browse our Energy & Insulation guides before the heating season.