How to Compare Energy Tariffs in the UK

Start with your own consumption

Find your latest annual statement or recent bills and note your electricity and gas consumption in kilowatt hours (kWh). Using your actual consumption produces a more meaningful comparison than using a generic “typical household” figure. If you have recently moved, use the best available estimate and revisit the comparison once you have more usage data.

Compare unit rates and standing charges together

The unit rate is what you pay for each kWh. The standing charge is a fixed daily amount. A tariff with a lower unit rate but a much higher standing charge may work differently for a low-use home than for a high-use household. Calculate both over a year instead of comparing only one number.

Check how you pay

Direct Debit, standard credit and prepayment arrangements can have different rates. Make sure you compare like with like. If a new quote assumes monthly Direct Debit but you currently pay on receipt of bill, the headline annual estimate may reflect both a new tariff and a new payment method.

Fixed or variable?

A fixed tariff normally fixes the unit rates and standing charges for a defined period, although your total bill can still rise if you use more energy. A variable tariff can change in line with supplier pricing and, where applicable, the Ofgem price cap. Compare certainty, exit fees and your view of future prices rather than assuming one type is always better.

Include incentives carefully

Referral credits, welcome bonuses and cashback can improve first-year value. Keep them separate from the ongoing tariff cost. A simple method is to calculate the estimated annual tariff cost first, then subtract any confirmed one-off incentive. That prevents a large sign-up bonus from hiding an expensive underlying tariff.

Questions to ask before accepting a deal

Check whether the quoted rate is fixed or variable, how long any fixed term lasts, whether there are exit fees, which payment method the quote assumes, whether smart-meter conditions apply, and what happens when the initial term ends. Save the tariff information you relied on so you can compare it with your first bill.

A worked comparison method

Start with the annual electricity and gas kWh from a recent bill. Multiply each fuel by the quoted unit rate, add 365 days of standing charges, then add the two fuel totals. Only after that should you apply a one-off referral credit or cashback. This prevents a large headline incentive from disguising a higher underlying tariff.