Five things I would never do as an energy expert
Keep your energy bills under control and get the best customer service with these five simple rules
Keeping track of rising and falling energy costs can feel like a full-time job. Add an increasingly wide range of tariffs on offer, and it’s easy to find yourself overwhelmed by the energy landscape.
Fortunately, there are a few simple steps you can take to ensure you get the best deal possible with an energy provider you can trust.
Which? energy expert James Aitchison has identified five common mistakes people make when picking their energy supplier and tariffs.
Read on to find out how to keep your energy bills as low as possible, avoid common switching pitfalls and keep your home as energy efficient as possible.
1. I wouldn’t stay on a variable tariff
'It’s looking likely that energy prices will drop on 1 July after going up in April. But while that's welcome news, prices are still higher than they were before the energy crisis began, and it’s unlikely that we will see the figures we were used to before 2021 any time soon,' James says.
'After spending the past few years paying variable rates that changed with every new price cap announcement, I recently took the plunge and signed up for a fixed energy deal.
'I know that now that I've fixed my rates in, I won’t benefit from the predicted price drop in July, but I’m happy to be off the energy cost rollercoaster and looking forward to at least a year of predictable prices.
'When you've fixed a deal, set a calendar reminder for a few weeks before your fixed tariff ends, so that you can start to compare prices and options for a new fixed tariff.'
2. I wouldn’t sign up for a tariff with a high exit fee
'The caveat to fixing a deal is that it's still worth bearing in mind that rates that are cheaper than the price cap now may no longer prove cost-effective if prices drop while you are fixed in', says James. 'I'd recommend choosing a tariff with low or, even better, no exit fees, so that you can bail out early if you need to.
'We’ve seen tariffs that can charge as much as £100 per fuel type if you end your contract early.
'While you might save money on your monthly payments by signing up to a cheap tariff with high exit fees, if you find yourself needing or wanting to switch before your contract ends, any potential savings you've made could well be cancelled out by having to pay to leave.
'When I switched providers earlier this year, I signed up for a tariff with no exit fees. It was slightly more expensive than some of the other options available at the time, but I’m safe in the knowledge that if a better deal comes along, I'll have options. So I'll keep my eyes peeled in July, should prices come down, despite being mid-way through a contract.'
See our table of the latest cheapest energy deals in our guide on how to get the best energy deal.
3. I wouldn’t only consider price when picking a provider
'Price is likely to be your primary concern in choosing a fixed energy tariff. However, there are other things to consider when switching providers, especially when many of the fixed deals you'll see will offer very similar rates,' says James.
'Cheaper monthly payments might lose their appeal if you run into a problem and your provider has terrible customer service. Suppliers that offer smooth and straightforward customer service when customers have questions and concerns can make all the difference to your overall experience, so they're worth considering - especially if the price difference isn't huge.'
Every year, we survey thousands of energy customers and conduct an in-depth, behind-the-scenes assessment of energy firms' practices to reveal the best – and the ones to avoid.
See how your supplier fared in our full table of the best and worst energy companies for 2025.
4. I wouldn’t sign up for a time-of-use tariff without ensuring I could make the most of it
'Time-of-use tariffs (TOU) offer cheaper electricity at specific off-peak times of day when demand on the National Grid is low. You'll need an electricity meter that can determine how much you use at certain times of day to be able to sign up to one.
'Economy 7 and Economy 10 were once the most common TOU tariffs, for which you'd have a two-rate meter that measured electricity used during either a 7-hour or a 10-hour off-peak window.
'Now, time-of-use tariffs are mainly reserved for those with EVs, solar panels, heat pumps or other renewable energy generators. The electricity you've used at certain times of day is logged using a smart meter, sending real-time readings automatically.
'If you are considering one of these tariffs, keep in mind that while your off-peak rates will be temptingly low, any electricity used the rest of the time will be charged at peak rates that are higher than the price cap. And these 'peak' times could run all the way from 7am until midnight. So if you can't shift the bulk of your use to the off-peak hours, you may end up overpaying for a lot of the electricity you use.
There’s no point in having a tariff that offers cheaper electricity overnight if you lack the appliances, heating system or EV to take full advantage. If you use a large amount of electricity during the day, you might be in for a shock when your first bill arrives. Look carefully at what the rates are, and when, so that you know you can make the most of your tariff.'
Got a time-of-use tariff? You may be surprised to learn which electrical appliances use the most energy, and therefore which you should make sure you use at off-peak times.
Find out more about time of use tariffs and how much your appliances cost to run.
5. I wouldn’t ignore the energy efficiency of my home
'When you look at the breakdown of a typical home's energy bill, most of us spend the bulk of that money on the gas we use to power our boiler, predominantly for central heating over the winter months. So, making your home as energy efficient as possible when it comes to heating is one of the best ways to make significant reductions to your bills,' James says.
'If you're renting your home, or short on time or budget, you might be limited as to what you can do, but our guide to draught proofing can help you get started with the surface-level updates that can make some immediate improvements and make your home cosier.'
Read more: make your home more energy efficient in one weekend
'For homeowners able to take a deeper dive, improving your insulation is a crucial first step. Our insulation guides can get you on the right track - find out where to start with our overview on how to insulate your home.
'There are several improvements that can help reduce your energy bills. Some are pricey, but if you pick the right ones, you (and the planet) will benefit in the long run.
'Our home energy planning service can help if you're trying to weigh up the different options available to you for your specific circumstances. It's free to use - just fill in a few key details about your home to explore the improvements you could make, what they'd cost, your options for tapping into government grants and other financial support, plus how much you could save on your bills.'
Home energy planning tool
Use our free tool and we'll build you a personalised plan to help you lower your energy bills
Start your plan
