What is a dual fuel tariff?
A dual fuel tariff is gas and electricity bought from the same supplier, on one account and usually one bill. Most UK homes are on one without ever choosing it. You signed up once, years ago, and never looked again.
That is exactly how the Do Nothing Default works. Your supplier is quietly counting on you to leave things as they are. The good news? A dual fuel setup is easy to check, and quite often easy to improve.
So is dual fuel the cheapest option for your home? It depends on a few things worth two minutes of your time. Here is how to work it out.
Is dual fuel cheaper than two separate deals?
Sometimes. Not always. A dual fuel tariff can work out cheaper because some suppliers knock a little off for taking both fuels, and you only manage one account. For a lot of households, that is the tidy, lower cost choice.
The catch is that the cheapest gas deal and the cheapest electricity deal do not always come from the same company. In some months, splitting your supply beats a single dual fuel bill. The only way to know is to compare both, side by side, for your postcode and your usage.
Either way, the gap tends to be modest, so convenience counts too. One bill, one login and one customer service line is worth something on a busy week.
5 quick checks before you pick a dual fuel deal
Before you lock in a dual fuel tariff, run through these five. They take minutes, and they can save you a fair bit over a year, depending on your usage.
Your dual fuel checklist
- Compare the total annual cost, not the monthly headline. Add gas and electricity together.
- Check the standing charges on both fuels, not just the unit rates.
- Look at the exit fees before you sign, so leaving early later does not sting.
- Confirm whether it is a fixed deal or a variable one that can move with the price cap.
- Ask whether the dual fuel discount is real, or just a nicer label on a pricier tariff.
Fixed or variable dual fuel: which is safer?
A fixed dual fuel deal locks your unit rates for a set term, so your prices hold steady even if the market climbs. A variable one moves with the wholesale market and the price cap, up or down.
Neither is automatically right. Fixing buys certainty and protects you from a rise, which many households find worth a small premium. Staying variable keeps you flexible if you think prices might fall. Our guide to fixed price energy tariffs walks through the trade off in plain terms.
When two separate deals can beat dual fuel
Dual fuel is not automatically the winner. If you use a lot more electricity than gas, say you run an EV or electric heating, a specialist electricity tariff can outperform a bundled dual fuel price. Our EV energy tariff guide covers that case.
Homes with solar panels, a heat pump or storage heaters are also worth checking separately. And if one supplier has a brilliant electricity rate but a weak gas one, you can lose money by forcing both onto a single dual fuel account.
None of this makes dual fuel bad. It just means the label is not a guarantee. Compare, then decide.
How to switch to a dual fuel tariff
Switching is quick, and you will not lose supply. You run a comparison, pick the cheaper option, and your new supplier handles the move, usually within about two weeks. Nothing gets dug up or disconnected.
You do not need to phone your old supplier to leave. Have a recent bill handy if you can, though most comparisons work fine on an estimate of your usage.
The average home pays around £1,663 a year for typical use under the current Ofgem price cap, so even a modest saving is worth a Tuesday night look. Doing nothing is the one option that never wins.
Frequently asked questions about dual fuel
- Does dual fuel always work out cheaper?
- No. It is often cheaper and simpler, but not guaranteed. The cheapest gas and electricity deals sometimes come from different suppliers, so it pays to compare both.
- Can I get gas and electricity from different suppliers?
- Yes. You can split your supply if two separate deals are cheaper for your home. It means two bills, but it can save money depending on your usage.
- Is dual fuel worse if I have an electric car?
- Not always, but heavy electricity users often do better on a specialist EV tariff. Check a separate electricity deal before committing to a dual fuel one.
- Will switching to dual fuel interrupt my supply?
- No. Your gas and electricity keep flowing. Only the billing and the company behind it change, usually within around two weeks.
