UK energy tariff comparison: how to find the cheapest deal

The energy price cap limits the maximum unit rate and standing charge that suppliers can charge on their default (variable) tariff. In April 2026, the cap is £1,738/year for a typical dual-fuel household. But this is based on average usage — if you use more, you'll pay more. The cap changes quarterly (January, April, July, October), so your bills fluctuate even on the default tariff. Crucially, fixed-rate deals are not limited by the cap, but they can be priced below it, offering both savings and certainty.

Start by finding your current annual consumption on a recent energy bill — you need your kWh usage for gas and electricity separately. Then use Ofgem-accredited comparison sites: Uswitch, Compare the Market, or Energy Helpline. Enter your postcode and usage to see available deals in your area. Look at the estimated annual cost, not just the unit rate, as standing charges vary between suppliers. Pay attention to exit fees on fixed deals — some are free to leave, while others charge £25–£50 per fuel if you switch early.

The best time to switch is 4–6 weeks before your current fixed deal ends or whenever you spot a tariff significantly cheaper than what you're paying. The switch process is handled entirely by your new supplier — you don't need to contact your old one. Take meter readings on the switch date and submit them to both suppliers. The whole process takes around 5 working days under the Energy Switch Guarantee, and your supply is never interrupted.

Switching gets you the best rate, but reducing usage saves even more. Smart meters (free from your supplier) help you see exactly where energy is being used. Turning your thermostat down by just 1°C saves around £80–£100 per year. LED bulbs use 90% less energy than old incandescents. Switching appliances off at the wall instead of standby saves £50–£65 per year on average. Track your monthly energy spending in SYM alongside your savings goals to see the impact of every small change.