Why is my gas and electricity bill so high? What to do about it

17 February 2021 | Stephen Marcus

Keeping on top of your bills is never much fun. And it’s especially tricky when a bill is higher than you expected – which can have a knock-on effect on your finances, and cause you to worry about it happening again.

To help with that, we’ll look at why your electricity bill could be too high, run through some common reasons for abnormally high gas and electricity bills, and share some tips on how to reduce them.

Why is my energy bill so high?

There are a number of reasons why your gas or electricity bill could suddenly be higher than you expected. Here are some of the things to bear in mind:

  • Price rises – if your energy supplier increases your gas or electricity prices, then your bills will go up. To see if they have, compare your most recent bill with the previous month. You should be able to compare the unit price between the 2 bills, to see if it’s increased. To learn more about how this works, check out our guide to understanding your energy bill.
  • Increased use – if you start using your gas or electricity more, it can also affect your bills. This can happen if you’ve bought new appliances, for example, or if there are more people at home than before.
  • Inaccurate estimates – your bills can be based on predictions of how much you’ll use, rather than meter readings. In this case, you can take meter readings yourself, to see if they’re different to the estimates. And if you want to stop worrying about estimates and meter readings, find out how a smart meter could give you greater control over your gas and electricity.
  • Heat loss – if you get a bill that seems high during the winter, it could be because of gaps in your home’s exteriors that let heat escape. This means your heating has to do more work, to warm your home back up again. Want to do something about it? Check out our guide to insulating your home, and how much it costs.

How much is the average gas and electric bill?

The average gas and electric bill in 2019 was £1,2891. This breaks down to £679 for electricity and £610 for gas, and was a rise of 2.8% on the previous year. The most surprising thing about rising bills is that we’re actually using less energy. But rising costs for energy suppliers have led to higher prices for customers.

To learn more, check out our guides to the average gas and electricity bill, and how to work out how much energy you use for heating.

What costs the most on your gas and electric bill?

Here are a few of the main culprits when it comes to energy-guzzlers – with some tips on how to minimise their impact:

  • Inefficient appliances – if your appliances are old and need replacing, they could be costing you dearly in wasted energy. Whether it’s a new boiler or a fridge and freezer, upgrading to energy-efficient appliances can lower your energy use and cut your bills.
  • Light bulbs – you can save £40 a year by changing from traditional incandescent bulbs to energy-efficient LED bulbs2. So if you’ve not yet made the switch, your lights could be an unnecessary extra expense. Find out more in our guide to energy-saving light bulbs.
  • Devices left on standby – just leaving things like your TV and radio on standby can add £35 to your electric bill each year3. Read more in our guide to standby energy, and for more energy-saving tips check out our guide to the top 14 ways to save electricity at home.

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7 questions to ask, if you think your energy bill is too high

1.  Is your bill based on accurate meter readings?

As we mentioned, your bill might be based on an estimate. It’s common for energy suppliers to only take a meter reading every 6 months, and then make a prediction of how much you’ll use the rest of the time. But sometimes they can get it wrong – particularly if you’ve just moved home, or if the weather is warmer (or colder) than usual for the time of year.

If you get a bill that seems too high, here’s what you should try first:

  • Check how it was calculated, to see if it’s based on real meter readings or an estimate
  • If it’s based on an estimate – take a meter reading, and then compare it with your bill to see if it’s accurate
  • If you find that your supplier has overestimated your energy use, contact them and ask for a new bill, taking your readings into account

Want to keep on top of how much energy you’re using? Find out how a smart meter could give you accurate bills, and help you save money

2. Are you on an expensive tariff?

If your energy bill seems too high, it’s time to check if you could get a better deal elsewhere. Are you on a standard variable tariff (check your bill to find this out)? If the answer is yes, then not only could you be getting a better deal, but your bills will go up by 5% in April 2021 – so it’s a good time to switch to a fixed rate tariff.

If you want a supplier with competitive prices and sustainable green energy, try switching to OVO. We offer 100% renewable electricity as standard4, and we’ll also plant a tree for every year you’re with us. Get a quote in 2 minutes.

3. Have you used more heating this winter?

Did your surprisingly high bill arrive during the winter? If so, it could be down to your heating. The average UK household uses over half its energy on central heating5, and in winter we use more of it – so it’s common that your bills will go up in the colder months.

And if it’s an especially harsh winter, then it’s likely to have an even bigger impact. A good example is the winter of 2018, when we were hit by the “Beast from the East”. With the UK hit by extreme low temperatures, the demand for gas rocketed, leading the National Grid to put out a warning that they were at risk of running out6!

While our changing habits can affect our energy use at different times of the year, the overall amount of gas and electricity we use has actually been going down over the past few decades7. To find out more, check out our guide to the average gas and electricity bill in the UK.

And for more on how to get the best value out of your heating, see our guides on the most efficient way to heat your home, and the ideal room temperature and thermostat settings.

4. Is your home poorly insulated?

The better insulated your home, the less energy you’ll use on heating. This is because your heating warms your home to the temperature you’ve set on the thermostat – so the more heat that escapes, the more often it will have to make up for the warmth that’s lost.

You can see how this works in the graph below. Here, we compare 3 homes with different insulation and airtightness levels.

heat gains and losses by house type

The super-insulated Passive House (Passivehaus) needs just 15 kWh/m2a of heating energy. This is a big contrast to a modern home, which uses 10 times the amount of energy. And for a leaky Victorian home, there’s an even bigger contrast, – as it needs 20 times the amount!

Not everyone can afford Passive House standards of insulation, but there are other ways to make your home more efficient – with options to suit every budget. The cheapest and easiest to do yourself is draught proofing, but loft insulation, cavity wall insulation and energy-efficient doors and windows are also affordable ways to improve your home’s energy-efficiency. 

To see all of the different ways to insulate your home, check out our complete guide to home insulation.

5. Do you use expensive fuel for heating?

Most UK homes use natural gas for their heating. Generally speaking, it’s an affordable way to heat your home – especially if you have a modern condensing boiler. (If you’re not sure what type of boiler you have, see our guide to different boiler types, and what’s right for you.)

But if your home uses electricity for heating, then it can end up being costly. This is because electricity costs more per kWh than gas. In fact, on average it’s more than 3 times the price8.

If it’s not possible to use gas in your home, then it’s worth thinking about other heating options. For example, you could use ground source heat pumps or air source heat pumps. They're a bigger investment, but they can save you money on your heating in the long-run, and help cut your carbon

Alternatively, you could try looking at oil heating systems. And for more inspiration, check out our guide to the world’s best low-carbon heating options.

To give you an example of just how expensive electricity is, we’ve graphed the cost of a unit of heat energy produced by different systems.

Energy cost comparison for heat: p/kWhth

6. Is your heating system sensibly programmed?

If you’re not able to improve the energy-efficiency of your home, don’t worry – you can still bring down your energy use by using your heating controls. 

According to the Energy Saving Trust, turning your thermostat down by just one degree can save the typical home around £60 a year. And if you’re wondering whether it’s more efficient to leave the heating on low all day, our guide to the most efficient way to use your heating will tell you all you need to know.

Wondering what the ideal room temperature is? As a general rule, anything below 18°C isn’t comfortable, and below 16°C is unhealthy. 20°C is the UK average, and is a good guide for living spaces. And if you’re thinking about alternatives to traditional radiators, our guide to underfloor heating tells you how energy-efficient and cost-effective it can be.

It’s also worth considering when you time your heating to come on and off, so that it’s only on when you need it. And extra heating controls, such as thermostatic radiator valves (TRVs), can give you greater control, letting you turn down the heating in rooms you’re not using.

By the way, it's also a good idea to bleed your radiators once a year, so they're working as efficiently as possible. Find out how to do it, and why a yearly radiator bleed can bring your heating costs down, with our handy guide.

7. Have you bought any new gadgets lately?

While your heating can often be the reason for a high bill, it can also be worth taking a look at your electricity use. 

If you’ve recently bought a new appliance, for example, it could be adding extra demands on your electricity. Especially if it’s known to be inefficient. Tumble dryers are one of the most expensive appliances to run, according to the Energy Saving Trust.

Below you can see how much energy different appliances use, and how it’s changed over time. On the one hand, the amount of energy used for refrigeration and lighting has gone down, as fridges and light bulbs have become more energy-efficient. But on the other, the amount used for “consumer electronics” has gone up, as we buy more gadgets. Check out our guide to reducing your electricity bills for more tips on how to cut your spending.

electricity consumption by household appliance type in the UK

How to check your bills are in order

Here’s a simple checklist to keep your bills on track:

Make sure your meter readings are accurate

  1. Check if you could save money by switching supplier
  2. Turn down your thermostat – and use extra heating controls where possible
  3. Invest in draught-proofing and insulation
  4. Choose a cheap heating fuel
  5. Watch out for inefficient appliances

How to resolve an issue with a high energy bill

If you have a high energy bill and you don’t think you’ll be able to pay it, you can arrange to set up a payment plan with your supplier. Before you call them, follow these steps:

  • Make a list of the money you have coming in (things like wages, pension, benefits)
  • Note down all your regular costs each month (such as rent or mortgage, plus council tax, water, broadband, food shopping, any other standing orders, and any debt repayments)
  • And finally, write down any big one-off payments you have coming up (like insurance or road tax)

Once you have all of this to hand, you’ll have a good idea of how much you can repay each month. Your supplier is obliged to help you find a solution, so don’t worry if you can’t repay much – the important thing is that you let them know, and make a plan. For more help with what to do, check out our guide on getting help with your gas and electricity bills.

Want to see if you could get a better deal? Switch to OVO for competitive prices and sustainable energy. We offer 100% renewable electricity as standard9 and we’ll plant a tree for every year you’re with us. Get a quote in 2 minutes.

Sources and references:

1  Energy Trends and Energy Prices published 26 March 2020 by the Department for Business, Energy and Industrial Strategy. Covering data for the fourth quarter of 2019. (Estimates are based on fixed consumption of 13,600 kWh of Gas and 3,600 kWh of Electricity).  

4  The renewable electricity we sell is backed by renewable certificates (Renewable Energy Guarantee of Origin certificates (REGOs)). See here for details on REGO certificates and how these work.


9  The renewable electricity we sell is backed by renewable certificates (Renewable Energy Guarantee of Origin certificates (REGOs)). See here for details on REGO certificates and how these work.

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