How Often Should You Compare Energy Prices to Avoid Overpaying?

Most UK households are overpaying for energy without realising it. The good news? The average saving we identify is between £200 and £500 and comparing energy prices takes just minutes. This guide explains when and how often you should compare to keep your bills as low as possible.

The Short Answer: At Least Once a Year (But Often More)

As a rule of thumb, you should compare energy prices at least once a year. But in reality, checking more often can save you even more.

Here’s a simple way to think about it:

  • Once a year is the bare minimum
  • Every 3–6 months is ideal for staying competitive
  • 6 weeks before your fixed deal ends is essential

Energy prices don’t stand still. With the price cap changing regularly and suppliers adjusting their tariffs, a deal that was competitive last year may no longer be the best option today.

Key Moments When You Should Always Compare Energy Prices

When Your Fixed Deal Is Ending

This is the most important time to compare. If you are on a fixed tariff and you don’t switch by the end date of your contract, you will go on to your supplier’s SVT and that’s rarely the cheapest option.

Action: Set a calendar reminder for 6 weeks before your contract ends. This gives you time to compare and switch before you roll onto a more expensive default tariff.

When the Price Cap Changes

The prices are reviewed in January, April, July and October by Ofgem. Each change can significantly affect your bills. 

Action: Use these dates as comparison prompts. You don’t need to switch every time the cap changes, but it’s worth checking if there’s a better deal available.

When You Move Home

Never assume your new property is on the best tariff. If you move house, you inherit the supplier of the previous tenant and will automatically be placed on its standard plan (also known as standard variable rate tariff) when the supplier takes you on.

Action: Compare energy prices as soon as you move. You might find significant savings by switching to a different supplier or tariff.

When Your Usage Changes

A new electric vehicle, working from home, or a new baby can shift your energy needs. What was the best deal for your old usage pattern might not be now.

Action: Run a fresh comparison when your household circumstances change.

When a Supplier Goes Bust

If your energy supplier collapses, you’ll be moved to a new supplier on a default tariff. This is a good time to compare and switch to something cheaper.

What Happens If You Don’t Compare Regularly?

The cost of staying on an expensive tariff adds up quickly.

Why SVTs are expensive:

  • A standard variable tariff, which is capped at £1,758 from 1 January to 31 March 2026, is usually the most expensive deal for customers
  • Suppliers save their best deals for new customers, not loyal ones
  • You’re paying the maximum allowed under the price cap, not a discounted rate

The real cost of inaction: If you stay on an SVT for just two years without comparing, you could be leaving £200–£700 on the table.

How the Ofgem Price Cap Affects When You Should Compare

What Is the Price Cap?

The Energy Price Cap was introduced on 1 January 2019 by regulator Ofgem, with the aim of preventing the millions of households on expensive variable tariffs from being ripped off. It limits what you pay for each unit of gas and electricity that you use, plus it sets a maximum daily standing charge (what you pay to have your home connected to the grid).

How It Works

  • Wholesale energy accounts for about 39% of a typical bill for a tariff priced at the maximum allowed under the current Price Cap from 1 January to 31 March 2026. It’s also what causes most of the change to the Price Cap every three months, as wholesale prices are constantly fluctuating
  • The cap changes quarterly, but it doesn’t mean you’re getting the best deal
  • It is not a cap on a total bill – customers who use more than £1,758 worth of energy will pay more while those who use less will pay less

Should You Fix or Stay Variable?

  • Fixed deals can sometimes beat the price cap and protect you from future rises
  • Variable deals follow the price cap, so you benefit if prices fall (like in April 2026)
  • The key: Compare both options based on your actual usage, not just the headline price

How Long Does Switching Energy Supplier Take?

One of the biggest myths about switching is that it takes weeks and disrupts your supply. It doesn’t.

The Timeline

The switch should be completed within five working days once you’ve signed up with a new supplier under Ofgem’s Energy Switch Guarantee. Some switches now take as little as one working day, depending on your meter type and supplier, although you can specify a later date if you prefer.

What You Need to Know

  • Your energy supply is never interrupted during the switch – it’s purely a billing change
  • You’re completely free to change your mind and cancel your switch without incurring any early exit fees at any time up to 14 days after the day you signed up, this is called your cooling off period
  • You should also be sent a final bill from your old supplier within six weeks of a switch

Even if you’re in a contract, it’s still worth comparing. You can see what’s available and decide if switching later makes sense.

How to Compare Energy Prices Properly

Comparing energy prices is straightforward. Here’s how to do it right:

Step 1: Gather Your Information

  • Have a recent energy bill handy (or your postcode and estimated usage)
  • Know your current supplier and tariff type
  • Check if you pay by Direct Debit, quarterly, or prepayment

Step 2: Enter Your Details

  • Enter your postcode to see rates in your area
  • Input your annual usage (in kWh) from a recent bill, or use an estimate
  • Select your payment method

Step 3: Compare What Matters

Don’t just look at the unit rate. Compare:

  • Unit rates (pence per kWh)
  • Standing charges (daily fixed cost)
  • Tariff type (fixed vs. variable)
  • Estimated annual cost (the total you’ll pay)
  • Exit fees (if you’re mid-contract)

Step 4: Switch in Minutes

Once you’ve found a better deal, switching is simple:

  • Confirm your choice
  • Provide your meter details
  • Your new supplier handles the rest
  • You’ll be switched within 5 working days

Tips to Make Sure You Never Overpay Again

A few simple habits can keep your energy bills in check long-term:

  1. Set a calendar reminder every 6 months to check your tariff
  2. Note your contract end date and diarise a comparison 6 weeks before
  3. Sign up for price cap update alerts so you know when rates change
  4. Keep a recent energy bill handy for accurate comparisons
  5. Don’t just look at the unit rate — factor in standing charges and any smart meter requirements
  6. Compare based on your actual usage, not “typical household” estimates
  7. Check for exit fees before switching mid-contract

FAQs

How often does the energy price cap change?

Every 3 months we review and set a level for how much an energy supplier can charge for each unit of energy and daily standing charge, under the price cap. The prices are reviewed in January, April, July and October.

Is it worth switching energy supplier right now?

The only way to know is to compare — it takes minutes and there’s no obligation. The average saving we identify is between £200 and £500, so it’s almost always worth checking.

How do I know if I’m on a standard variable tariff?

Check your bill or contact your supplier. If you’re not on a named fixed deal with an end date, you’re probably on an SVT. While many suppliers use clear names such as “Standard Tariff”, which can easily be identified as the default rate, others use misleading names like “Flexible Saver”.

Can I switch if I have a prepayment meter?

Yes. For prepayment meter customers, Ofgem’s energy price cap will be applied to the price you pay for each unit of energy. The unit price varies regionally, by payment method and depends on the time of day that the energy is used but the majority of prepayment meter customers will see their unit prices decrease and electricity standing charges increase to be in line with those set by Ofgem from 1 April 2026.

Does comparing energy prices affect my credit score?

No. Comparing energy prices does not involve a credit check, so it won’t affect your credit score.

What if I’m locked into a contract with exit fees?

You can still compare to see what you’d save by switching. Calculate whether the exit fee is worth paying based on your potential savings. Many tariffs have exit-fee-free windows near the end of the contract.

How much can I realistically save?

It depends on your current tariff and usage, but the average saving we identify is between £200 and £500 per year. Some households save even more.

Conclusion

The cost of not comparing is real. A standard variable tariff, which is capped at £1,758 from 1 January to 31 March 2026, is usually the most expensive deal for customers. By comparing energy suppliers just once a year, or ideally every 3–6 months, you can avoid overpaying and keep hundreds of pounds in your pocket.

The bottom line:

  • Compare at least once a year (minimum)
  • Check every 3–6 months for the best deals
  • Start comparing 6 weeks before your fixed deal ends
  • Switching takes just 5 working days and won’t disrupt your supply
  • Simply Switch makes it quick, impartial, and easy to find the right tariff for you