Quick answer: the cheapest gas tariff in the UK
- Typical annual gas bill
- £766
- Medium home, gas only
- Gas unit rate
- 5.7p/kWh
- Capped maximum
- Gas standing charge
- 29.1p/day
- About £106/year
- Realistic gas saving
- £40 to £180
- Right tariff shape, your usage
Why the headline gas rate misleads almost everyone
Most "cheapest gas supplier" articles compare the unit rate, the price you pay for each kWh (kilowatt-hour, the unit your meter counts and your supplier bills you in). The trouble is that under the Ofgem cap, every standard variable gas tariff sits within a few pennies of each other. British Gas, EDF, Octopus, E.ON Next and Scottish Power all charge close to 5.7p per kWh, because the cap forbids them charging more.
That makes the headline rate almost useless as a ranking tool. The real differences sit elsewhere, in three less-visible levers.
- The standing charge, a daily fee you pay before burning any gas;
- The dual-fuel discount split, which often loads savings onto electricity and leaves gas at the cap;
- The timing of your switch, because fixed deals are bets on the next two or three cap quarters.
Get those three right and you can save £40 to £180 a year on gas. Get them wrong and a "cheap" fixed deal can actively cost you more than doing nothing.
What most "cheapest gas supplier" listicles miss
Compare-the-market style listicles tend to make three structural errors. They sort by unit rate, ignore standing charges, and treat any fixed deal "below the cap" as automatically cheaper. None of that holds up in a capped market.
Error 1: ranking by unit rate
Under the cap, supplier unit rates differ by pennies. Sorting tariffs by unit rate puts a rounding error in charge of your decision.
Error 2: ignoring standing charges
Gas standing charge is now about £106 a year before you burn any gas. For a small flat using 5,000 kWh, that fee is a third of the total bill.
Error 3: ignoring exit fees
Exit fees on fixed gas deals run £30 to £100 per fuel. Switching mid-contract wipes out most "headline" savings unless you are within the 49-day waiver window.
A fixed deal "5% below the cap" is not automatically cheaper.
If the cap falls 6% next quarter, that "cheap fix" is now above the new variable price, and you cannot leave without paying an exit fee. Compare every tariff against where the cap is likely to be, not where it sits today.
How the UK gas market actually works
Suppliers buy gas on the wholesale market, mostly through the National Balancing Point (NBP), the UK gas hub where producers, traders and suppliers settle contracts. Wholesale prices rise in winter, when demand peaks, and fall in spring and autumn. The Q2 2026 cut was partly a wholesale story and partly a political one: levies for green schemes were moved off bills in the Autumn Budget 2025.
Ofgem rebuilds the cap every quarter using six ingredients: wholesale cost, network charges, policy costs, supplier operating costs, a small EBIT margin (about 2.4% of revenue), and a "headroom" allowance. The cap is then expressed as a typical annual bill for a household using 11,500 kWh of gas and 2,700 kWh of electricity, paying by direct debit, GB average.
Why "challenger" gas-only suppliers collapsed
Between September 2021 and the end of 2022, more than 30 UK suppliers went bust. Bulb, Avro, People's Energy, Together Energy and many others sold gas at fixed prices and hedged badly when wholesale gas tripled. The customers were rolled over to "supplier of last resort" providers, almost always large incumbents like British Gas, Octopus or E.ON Next.
The lesson is structural: a "cheapest gas tariff" advertised by a thinly capitalised challenger is a different product from the same headline price on a major supplier. Stress-test the supplier, not just the price.
How dual-fuel "discounts" really work
A dual-fuel deal sells you gas and electricity on the same tariff. The supplier saves on billing and acquisition costs, and passes part of that saving to you. The headline discount sits anywhere between £20 and £80 a year. In practice, suppliers often park the gas side at the cap and load all the discount onto the electricity unit rate, because most consumers compare on the electricity figure they remember.
When you ask for a quote, request the gas-only annual cost on your actual kWh. If it equals the cap-implied figure (around £766 for a medium home), the "dual-fuel discount" is not cutting your gas bill at all.
What this means for your gas bill
The standing charge is now the silent fee that decides whether you "feel" the cap. At 29.1p per day, you pay roughly £106 a year before you burn a single kWh of gas. For a medium home using 11,500 kWh, that is about 14% of the gas bill. For a small flat using 5,000 kWh, it is closer to 30%. For a heat-pump-supplemented home using 2,000 kWh of gas just for cooking and hot water, the standing charge is the entire bill.
Small flat
~30%
of the gas bill is standing charge for a 5,000 kWh user. The unit rate barely moves the needle.
Medium 3-bed home
~14%
of the gas bill is standing charge for the Ofgem benchmark 11,500 kWh home. Unit rate dominates.
Prepayment penalty
£40 to £80
extra per year on gas for a prepayment customer versus direct debit, on the same usage.
If you fall into the small-flat or heat-pump-supplemented group, you are reading the wrong content when you search for "cheapest gas unit rate". Your bill is mostly fixed by the standing charge, not the variable cost of gas.
The no-standing-charge gas tariff has a break-even point
A no-standing-charge gas tariff scraps the daily fee and charges a higher unit rate to compensate. It sounds like a clear win for low users. The maths is more interesting than that.
Suppose the cap charges 5.7p per kWh and 29.1p per day. An illustrative no-standing-charge tariff might charge 8.2p per kWh and 0p per day. The extra 2.5p per kWh on the no-standing tariff has to make up the £106 a year you would have paid in standing charge.
Break-even calculation
Annual standing charge saving = annual extra unit cost
£106 = kWh × 2.46p ÷ 100
Break-even = 4,316 kWh a year.
Below about 4,316 kWh a year, the no-standing-charge tariff is genuinely cheaper. Above that, it is actively worse. A medium home using 11,500 kWh would pay roughly £943 on the no-standing tariff, against £766 on the capped tariff: a loss of about £177 a year.
This is the kind of arithmetic that "Top 10 cheap gas suppliers" articles never run. Always work out your own break-even before signing up for any tariff that looks structurally different from the cap.
Gas tariff break-even calculator
Enter your annual gas use and a proposed tariff. The calculator shows whether you would save or lose money against the Q2 2026 Ofgem price cap, or against an illustrative no-standing-charge tariff. Updates as you type.
Your inputs
Your result
- Your annual gas bill
- Standing charge share of bill
Saving vs baseline
At your usage of kWh, your proposed tariff is than the Q2 2026 Ofgem price cap. At your usage of kWh, your proposed tariff is than the illustrative no-standing-charge tariff. The no-standing-charge tariff only beats the cap below kWh a year.
Estimate uses the current Ofgem price cap (Q2 2026, GB average, direct debit, VAT included). The no-standing-charge tariff is illustrative; real offers vary.
Three gas tariff archetypes, same usage, very different bills
Here are three structurally different gas tariffs applied to the same medium home using 11,500 kWh a year. Same consumption, different shapes, different bills. This is what supplier "lists" hide when they sort by unit rate.
| Tariff archetype | Unit rate | Standing charge | Annual gas cost |
|---|---|---|---|
| Standard variable at cap | 5.74p | 29.09p | £766 |
| Fixed deal, 3% below cap | 5.57p | 28.22p | £744 |
| No-standing-charge tariff | 8.2p | 0p | £943 |
The "no-standing-charge" archetype looks attractive on paper, but at a medium-home usage of 11,500 kWh it ends up almost £177 more expensive than the standard cap tariff. It only wins for very low gas users.
What you should actually do to find the cheapest gas
Forget brand shopping. Run these five checks instead.
-
1
Compare standing charge before unit rate if you use under 8,000 kWh
For low and small-flat gas users, a 1p/day cut in standing charge (£3.65 a year) is worth more than a 0.5p/kWh cut in the unit rate (£25 a year on 5,000 kWh). For very low users, prefer no-standing-charge tariffs and run the break-even yourself.
-
2
Check whether a "dual-fuel discount" really cuts your gas
Ask the supplier for the gas-only annual cost on your actual kWh. If it equals roughly £766 for a medium home, the dual-fuel discount is electricity-side only and your gas is at the cap.
-
3
Use the 49-day exit-fee waiver window
In the final 49 days of a fixed deal, you can switch supplier without paying exit fees. Note the contract end date in your calendar two months before, and shop around in that window. It is the only stress-free moment to change.
-
4
Reject prepayment if you can pass a credit check
Prepayment gas tariffs run £40 to £80 a year more than direct debit on the same usage. The Ofgem cap differs by payment method, and direct debit always wins. Smart meters can switch from prepayment to credit mode without a meter change.
-
5
For heat-pump-ready homes, do not fix
If you plan to install a heat pump or supplement gas with electric heating in the next 12 to 24 months, your gas usage will drop sharply. Locking into a 2-year fixed deal puts you on the wrong side of the standing-charge maths. Stay variable.
Quick start. Pull up your latest gas bill, find the annual kWh figure, then plug those numbers into the calculator above. Compare your current tariff against the cap and against a no-standing-charge tariff. Two minutes of arithmetic beats any "Top 10 cheap gas suppliers" article.
The bottom line on cheap gas in the UK
Since the Ofgem cap, choosing a gas supplier is mostly about tariff shape, not brand. Unit rates cluster within pennies of each other. The real cheap-or-expensive levers are the standing charge, whether a dual-fuel discount actually touches your gas line, and whether you time your switch around the 49-day exit-fee waiver window.
For a medium home using 11,500 kWh, you can expect to save between £40 and £180 a year by picking the right tariff shape. For a small flat or a heat-pump-supplemented home, the standing charge matters far more than any unit rate.
If you remember one thing from this guide: do not rank gas tariffs by unit rate alone. Pull out your last bill, find your annual kWh, and use the calculator above. Your "cheapest gas supplier" is the one that fits the shape of your own consumption, not the one that wins a headline league table.
Frequently asked questions
Next steps and related reading
If you also want to find a cheaper electricity tariff, want to dig into individual tariff types, or are unsure of your kWh usage, the guides below are the natural next stops. They use the same data and method as this page.