Compare gas and electricity prices (UK)

Decision checklist: who comparing suits best

• You’re happy to share basic details (postcode + usage) to get accurate estimates.
• You can switch online and manage an account digitally.
• You want to check for better value before your current deal ends.
• You’re comfortable weighing price vs contract length and fees.

When it may not be the right moment

• You’re in the middle of resolving billing or meter issues — fix these first.
• You’re on a fixed deal with high exit fees and only a short time left.
• You don’t know your meter type (standard vs Economy 7) and can’t access it yet.
• You’re moving within weeks — you may prefer to wait and compare at the new address.

Scenario A: low electricity usage flat (standing charge dominates)

Home: 1–2 bed flat, efficient appliances, no electric heating.
Annual electricity use: 1,800 kWh.

Even though Deal 1 has the cheaper unit rate, Deal 2 is estimated to cost less because the standing charge is lower. This is common for low usage households.

Scenario B: family home on gas central heating (unit rate matters more)

Home: 3–4 bed house, gas boiler.
Annual use: Electricity 3,100 kWh, Gas 12,000 kWh.

Here, a small change in the gas unit rate can outweigh a higher standing charge because annual gas usage is high. That’s why you should always compare using your kWh.

Common comparison mistakes

• Comparing unit rates but ignoring standing charges.
• Using out-of-date usage (e.g. pre-heat-pump or pre-EV).
• Mixing payment methods (Direct Debit vs prepayment) between quotes.
• Assuming “dual fuel discount” always makes it cheaper.
• Forgetting to check whether prices are fixed, variable, or tracker.

When switching can be delayed

Most switches are straightforward, but delays can happen if there’s a meter dispute, address mismatch, or debt assignment on a prepayment meter.

Is it better to compare in kWh or in pounds?

kWh is best because it’s independent of past prices. If you only know what you pay per month, you can start there, but your results may be less accurate until you confirm annual kWh from a bill.

What’s the difference between the price cap and my tariff price?

Ofgem’s price cap limits the maximum level of certain charges for standard variable tariffs (and some default tariffs). It’s not a cap on your total bill — your usage still determines what you pay.

Do I need to compare gas and electricity together (dual fuel)?

Not always. Dual fuel can be convenient, but it isn’t automatically cheaper. Sometimes the best-value electricity deal and best-value gas deal are with different suppliers.

Can I switch if I rent?

Usually yes if your name is on the energy account and you pay the supplier directly. If energy is included in rent or the landlord controls the account, you may not be able to switch.

Will switching affect my smart meter?

Smart meters generally keep working after you switch, but the “smart” features (like automatic readings) can vary depending on compatibility and the supplier. If in doubt, confirm during the switch journey.

What if I’m on a prepayment meter?

You can compare and may be able to switch, but options can be more limited and eligibility may depend on debt levels and meter arrangements. Always select “prepayment” when comparing so rates are like-for-like.

How do I find my tariff and rates?

Check a recent bill or your online account. Look for “unit rate” (p/kWh) and “standing charge” (p/day) for each fuel. If you have Economy 7, you’ll see separate day and night rates.

Does a longer fixed tariff always mean better value?

Not necessarily. Longer fixes can offer stability but may have higher rates or higher exit fees. Consider how likely you are to move home or want to switch again within the term.

Page ownership

Written by

EnergyPlus Editorial Team

Reviewed by

Energy Specialist

Last updated

February 2026

How we assess “price” on this page

We focus on the components that determine a household’s energy cost:

• Unit rate (p/kWh) for gas and/or electricity
• Standing charge (p/day) for each fuel
• Meter type (standard, Economy 7, smart, prepayment)
• Payment method (e.g. Direct Debit vs prepayment)
• Tariff structure (fixed, variable, tracker) and key terms (exit fees, eligibility)

The example calculations use a simple formula: annual cost = (unit rate × annual kWh) + (standing charge × 365). This is a helpful approximation, but your billed amounts can differ due to VAT rounding, billing periods, discounts, and how your supplier estimates or reconciles Direct Debit over the year.