Cheapest Energy Supplier in the UK
"Cheapest" depends on your usage, region and tariff type. The sticker price rarely tells the full story — exit fees, admin charges and standing charges can wipe out a £100/yr saving in months.
"Cheapest" depends on your usage, region and tariff type. The sticker price rarely tells the full story — exit fees, admin charges and standing charges can wipe out a £100/yr saving in months.
Tap any supplier to see their tariff details, hidden fees and anything we think is worth flagging — so you can choose with eyes open.
Annual costs are calculated on 2,500 kWh electricity and 9,500 kWh gas, single-rate Direct Debit, using each supplier's stored unit rates and standing charges. Supplier tariff figures checked monthly; the date each record was last checked is shown above.
We track the major Great Britain household suppliers: Octopus Energy (including Bulb and former Shell Energy Retail customers), British Gas, E.ON Next, EDF Energy, OVO Energy, ScottishPower, So Energy, Co-op Energy and Utility Warehouse.
Suppliers are selected by domestic customer numbers and whether they are open to new household customers. The list is not comprehensive — smaller and regional suppliers are not yet tracked.
Supplier records and tariff figures are checked at least monthly.
Rankings are independent of commercial relationships. Affiliate commission never influences inclusion, scoring or ordering.
Our flagship independent ranking of UK energy suppliers, covering customer service, tariff competitiveness, complaint performance and consumer risk.
Got a smart meter? Read our smart meter switching advice to see what happens to your meter when you change supplier.
PowerGuardian's comparison shows the true annual costincluding standing charges and surfaces every flaw — exit fees, admin charges, customer-service issues — so you don't get caught out.
See the full comparison on our homepageBefore you compare, make sure you're being billed on real readings, not estimates. If your meter isn't sending data, fix common smart meter problems so your new supplier starts you on accurate figures.
Explore this topic
This page sits inside our guide to comparing UK energy suppliers, which brings together supplier performance scores, tariff types and the switching process.
Free calculators picked for this topic.
Is switching worth it right now? A decision framework using the current cap and fixed-deal evidence.
Open CalculatorCompare what you pay now against the deals we list, using figures you enter.
Open CalculatorEnter your kWh usage, unit rate and standing charge for daily, monthly and annual totals.
Open CalculatorIndependent PowerGuardian scores out of 100 for relevant suppliers, as at 21 September 2026.
Octopus continues to lead the UK market on customer service and complaint handling, backed by genuinely competitive smart tariffs and strong financial backing. The clear front-runner on our intelligence dashboard.
Compare SupplierBacked by ESB, So Energy combines competitive fixed tariffs with consistently strong service scores. A solid mid-market performer.
Compare SupplierThe UK's largest supplier remains financially rock-solid but service and complaint metrics continue to lag the market, with smart-meter billing delays a recurring theme.
Compare SupplierQuick answers to the questions people ask most about this topic.
Free PowerGuardian Report
Which UK suppliers offer the best value right now — ranked on price, tariff fairness and overall cost across typical household usage.
Create your free personalised dashboard to keep track of useful guides, calculators and savings opportunities.