How to compare electricity tariffs

Use annual kWh where possible

Your annual electricity use is the cleanest starting point. It may be shown on your bill, supplier app or smart meter account. Using your own kWh is better than using a national average, because homes vary widely.

The Electricity Tariff Comparison Calculator uses annual kWh, unit rates and standing charges to compare two tariffs over the period you choose.

Unit rate and standing charge do different jobs

The unit rate is the price for each kWh of electricity you use. The standing charge is the daily charge for being connected, whether you use much electricity or not.

A low-use home can be hit harder by a high standing charge. A high-use home is usually more sensitive to the unit rate. That is why comparing only one number can be misleading.

Include exit fees

If leaving your current tariff costs GBP 50, the new tariff needs to save more than GBP 50 before you are ahead. The shorter the comparison period, the harder it is for a small monthly saving to cover an exit fee.

Also check whether the new tariff has its own exit fee. That may matter if prices drop or your circumstances change later.

Check the small print before switching

• Whether prices include VAT.
• Whether direct debit is required.
• Whether the tariff needs a smart meter.
• How long the fixed term lasts.
• Whether gas is separate or part of a dual-fuel deal.
• Whether regional rates differ from the headline offer.

Monthly direct debit is not the same as yearly cost

Suppliers often smooth payments across the year, so the monthly direct debit may not match the electricity used in that exact month. A lower direct debit can feel cheaper, but the annual tariff cost is the better comparison.

Look at the estimated yearly cost, the unit rate, the standing charge and your annual kWh together. If the new tariff changes the direct debit only, but not the underlying rates, that may be a payment change rather than a real price saving.

Compare like with like

Try to compare the same payment method, meter type and region. A tariff advertised with direct debit pricing may not match prepayment or standard credit pricing. Economy 7 and other multi-rate meters need separate day and night rates, so a simple single-rate comparison may not be enough.

Useful tools