Avoid Hidden Costs When Switching Dual Fuel Energy Deals

A dual fuel tariff is when you get both your gas and electricity from one energy supplier. You will have just one energy account for both. This means you only deal with one point of contact. You also get one bill to pay. Sometimes, the supplier gives you a dual fuel discount as well.

Changing to a new dual fuel deal can help you pay less for your energy bill. But there are things to be careful about. The deal might have exit fees. There could be high daily standing charges. Some plans use variable tariffs that can be hard to understand. All these might mean you do not save as much money as you thought.

What hidden costs should you check in dual fuel tariffs?

• Daily standing charges – Ofgem’s July 2025 data says an average household pays about 54p each day for electricity and 34p each day for gas. This adds up to around £320 every year just for the fixed costs.
• Exit fees – Most fixed tariffs have a charge of £30–£50 for each fuel if you leave early. So if you switch too soon, it could cost up to £100.
• Meter readings – If you do not use a smart meter, meter readings might not be correct. Bills could be based on guesses, so you may pay more until things get sorted.
• Prepayment tariffs – People who use prepayment meters often get higher unit rates. There are also fewer discounts for them.

Why do standing charges make such a difference?

Standing charges are taken every day, even if you use only a little bit of energy. If you have a home that uses less energy, these fees can be so high that the savings from a dual fuel discount are not enough to make up for them. But if your home uses a lot of energy, these same charges will not feel as important, because they are just a small part of the whole bill.

Worked example 1: Low-use household

• The electricity standing charge comes to 53.68 p times 365 days. This is £196 each year.
• The gas standing charge is 34.03 p per day for 365 days. This adds up to £124 each year.
• When you put both standing charges together, they make £320 each year.

If the home spends just £500 on energy in one year, and this is based on unit rates:

• £500 plus £320 equals an £820 total bill.
• Standing charges are 39% of the total bill.

Worked example 2: High-use household

• The standing charges are fixed. This means they stay the same at £320 a year.
• If your home uses £2,000 in energy in a year:
• £2,000 plus £320 makes the total bill £2,320.
• Standing charges are 14% of the total bill.

This shows why:

• If you live in a small home or do not use much gas, the standing charges make up most of your dual fuel bill.
• If you have a large household and use more energy, the standing charges are only a small part of your dual fuel bill, so a dual fuel deal is often the best choice.

How do exit fees affect switching to a new supplier?

Exit fees can take away your savings if you change plans at the wrong time.

If you are on a fixed contract with your current deal, it could be better to wait until it ends. But, if the new tariff helps you save much more money, you may want to switch over now.

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Can variable tariffs save more than fixed tariffs?

• Variable tariffs link to the energy price cap. Ofgem set the price cap at £1,720 for July to September 2025. It will be at £1,755 from October 2025.
• If wholesale energy prices drop, variable tariffs can help you get cheaper energy bills.
• But they can go up, so future rises in energy prices may make your annual bills higher.

A fixed tariff keeps the same unit rates, so you get more stability with your bills. But, if you leave before the end of the contract, you will usually have to pay early exit fees.

What problems can happen when switching suppliers?

1. Incorrect meter readings – If there is an estimate, you may have a delay or could get overbilled.
2. Exclusive discounts – Some deals online are only there if you sign up in the right way. You might not get them if you miss a step.
3. Customer service issues – If the support from energy companies is poor, it can take longer to fix billing mistakes.
4. Supply delays – A switch may take weeks, mainly with smaller energy companies.

The Energy Switch Guarantee helps make sure your power keeps running. But it does not protect you from hidden fees or bad customer service.

When are separate suppliers a better option than dual fuel?

Dual fuel is not always the best energy deal.

• Single fuel can cost less for households that use a lot of electricity or very little gas.
• Some suppliers have special EV tariffs or electricity deals for renewable energy. These options are not always there with dual fuel.
• If you do not use much gas, having a separate gas and electricity supplier can help cut costs.

How do smart meters help avoid hidden costs?

• Give exact meter readings, so you pay for the energy usage you really use.
• Show daily energy use patterns. This helps you see if a fixed tariff or a variable tariff is better for your home.
• Lower the risk of back-billing or problems with your supplier.

Getting a smart meter is free from most energy companies. It is one of the best ways people can stop hidden costs.

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What should you do before switching to a new tariff?

Switching to a new dual fuel deal can help you lower your energy bill. But you need to be ready before you do it. If you change too fast, you may pay hidden costs. You could miss out on good discounts as well. Also, there are times when you get stuck with early exit fees. Here’s what you should do:

1. Gather your recent bill
   Get your latest bill and look at your real energy usage in kWh. It’s better to use actual numbers from your statement instead of guesses when you do an energy comparison. Real details make the comparison fit your home’s real needs.
2. Use an energy comparison tool
   Type in your postcode and how much energy you use. This will let you compare the unit rates and daily charges from different suppliers. With this info, you see the real price of a dual fuel tariff, not just discounts shown up front.
3. Compare tariff types carefully

   • Fixed tariffs: keep your unit rates steady, giving you stability. But, there can be exit fees if you leave early.

   • Variable tariffs: follow the energy price cap and can change when wholesale energy prices go up or down.

   • Prepayment tariffs: often cost more and have fewer discounts. Your type of meter also matters with these.

4. Check contract terms for fees
   Check your current deal for any early exit fees, which can be up to £100 for both fuels. These fees might take away any benefit of moving to a new supplier before your contract ends.
5. Confirm the Energy Switch Guarantee
   Make sure your new supplier offers the Energy Switch Guarantee. With this, your energy supply stays on without breaks, the switch is done in 5 working days, and you won’t be charged twice for the same

By doing these things, you avoid paying more than you need to and find the energy deal that fits your usage. This also helps you save money on your energy bills. The best way to be sure you get the best dual fuel deal is to keep checking energy prices often. You should do this every time your fixed tariff ends or when the price cap changes. This makes sure you always get a good energy deal and keep your energy bills cheaper.

FAQs: Hidden Costs & Dual Fuel Switching