With energy bills still keeping everyone on their toes, we’ve all heard the usual tips about turning down the thermostat or switching off stand-by lights.
However, if you really want to know how to keep those costs under control, it pays to look at what the pros do in their own homes—or, more accurately, what they don’t do. We sat down with a handful of UK energy experts to find out the specific habits, appliances, and so-called hacks they completely avoid to keep their houses efficient and their bank accounts happy. Here are some of the biggest mistakes they advise against making.
Forgetting when your fixed deal runs out
Fixed energy deals usually run for 12, 18, or 24 months, and when yours ends, your supplier moves you onto their standard variable rate without you needing to do a thing. That might sound convenient, but variable rates are tied to the price cap, which is currently going up, so you can find yourself paying noticeably more simply because you didn’t notice the clock had run out. It happens to a lot of people because the end date tends to feel distant when you first sign up.
Your supplier is required to let you know 49 days before your deal expires, so watch out for that letter or email. The good bit is that you can switch during those final 49 days without being hit with exit fees, which gives you a clear window to find something better. Your tariff end date should be visible in your online account or in your supplier’s app, and setting a calendar reminder a month or two beforehand can save you from drifting onto a more costly rate without realising.
Using average usage estimates when you’re getting a quote
When you compare energy deals, you’re often asked to pick from low, medium, or high usage categories rather than putting in your actual figures. It feels quicker, and for a rough ballpark, it can do the job, but it’s not a reliable way to know what you’d actually pay if you committed to a tariff. The energy regulator recently reduced the amounts of gas and electricity used in each of those standard scenarios, which means quotes based on them can look more attractive than your real bill would actually turn out to be.
Suppliers adjust your direct debit based on how much energy you actually use, so if you’ve been quoted on a medium usage estimate, but you’re running a busy household with the heating going constantly, you’ll end up owing more than expected. It takes five minutes to find your actual annual usage in your account or on a recent statement, and inputting that instead makes any quote you get far more accurate and much less likely to surprise you down the line.
Assuming bigger suppliers mean better service
Six large suppliers cover around 92% of UK households, and a lot of people have never switched away from whoever they were with when they first moved in. It’s understandable, switching can feel like effort, but staying put out of habit rather than choice means you might be with a company that doesn’t actually serve you well. Size and reputation don’t always line up when it comes to energy.
Research into customer satisfaction consistently shows major differences between suppliers, and some of the biggest names sit near the bottom when it comes to how customers rate their service, value for money, and general reliability. Smaller suppliers have ranked highly in independent assessments in recent years, so they’re worth including when you’re comparing options. Looking at customer reviews before you commit gives you a clearer picture than going by name recognition alone.
Getting swayed by rewards and extras
Some energy tariffs come with perks attached, things like boiler cover, cashback, or discounts on other services. It’s easy to let those feel like a good deal, especially if boiler cover is something you’ve been meaning to sort anyway. But the most important factor is whether the underlying energy price is competitive, and bundled extras can make that harder to see clearly when you’re comparing options side by side.
Boiler cover is the one to think about carefully because if you’ve already got it through home insurance or a separate policy, you’d be paying for the same thing twice. Beyond that, consider whether you’d actually use whatever’s being offered. After all, a reward that goes untouched doesn’t add any real value to a tariff that might be costing you more per unit than the alternatives available.
Not reading the key parts of the small print
Reading a full set of terms before signing up isn’t something most people do, and that’s fair enough. But there are a handful of specific things worth looking at before you commit, since suppliers tend to promote the headline benefits of a deal without making the limitations obvious. A few minutes on the details can save a much bigger headache later.
Exit fees are the main one. If you need to leave before the contract ends, those fees can range from nothing to a meaningful amount depending on the supplier and tariff. Also check how your direct debit is calculated, whether it’s a fixed monthly amount or based on actual usage. If you export solar energy, find out what rate a new supplier would pay you, as that can vary. And if you’re eligible for the Warm Home Discount, confirm the new supplier participates in the scheme before switching because not all of them do.
Not keeping an eye on your meter readings
Smart meters are designed to send readings to your supplier automatically, and most of the time they do. That being said, they don’t always work perfectly, and if readings aren’t getting through, your bills may be estimated rather than based on actual consumption. Estimated bills can swing in either direction, and finding out months later that you’ve been underpaying and owe a lump sum can be a real headache.
If you don’t have a smart meter, submitting a reading once a month keeps your account accurate and avoids corrections further down the road. Check occasionally whether readings are showing as actual or estimated in your account because anything marked with an ‘E’ means your supplier is making an educated guess rather than measuring what you’ve actually used. It’s a small habit that makes a disproportionate difference to how accurate your bills are over time.
Staying put because switching feels like too much effort
A lot of people haven’t switched supplier in years, not because they’ve decided their current deal is the best available, but because the process feels complicated. In practice, it’s become much more straightforward. Most switches complete within a couple of weeks, there’s no interruption to your supply, and nothing needs to happen at your end beyond choosing a new deal and confirming a few details.
With costs expected to remain high going into autumn, it’s at least worth checking whether a fixed deal would save you money. Even if you compare and decide to stay where you are, you’ll know you’re not leaving anything on the table. A comparison takes around twenty minutes, and at worst you come away reassured that your current setup is doing the job.
