How the Energy Supplier Score is calculated

Customer service · 30%

The score comes from the Citizens Advice Energy Supplier Star Rating, published every quarter (currently Q4 2025). The published star rating out of 5 is rescaled to a score out of 10 by doubling it. That rating blends complaints volumes and how well they are handled, ease of contact, accuracy of bills and switching, and the customer guarantees a supplier offers. It is our highest-weighted area because day-to-day service is what customers feel most. Suppliers under roughly 25,000 accounts sit outside the headline Citizens Advice table, though a rating for some can still be found under the tool's own supplier dropdown. Being smaller, they carry less standardised public data overall, so where there is no defensible figure for an area we show a question mark rather than a guessed number.

Fairness & transparency · 18%

An evidence-based composite. Each supplier starts at a baseline of 10, reduced for recent regulatory and conduct failings: Ofgem enforcement, fines and redress orders, Energy Ombudsman outcomes, and billing-accuracy or vulnerable-customer issues. The specific basis for a supplier's score is listed on its profile so it can be checked. This area captures how a supplier treats people, especially when something goes wrong, which is where the gap between good and poor suppliers is widest.

Tariff range · 15%

A count of how many of ten tariff types a supplier offers, scaled to a score out of 10. The ten types are: standard variable, fixed (1 year), fixed (2 years or more), EV, heat pump, export/SEG, smart/agile/time-of-use, tracker (daily wholesale-linked), bundle (multi-service), and a 100% renewable option.

A tracker is credited only where a genuine daily wholesale tracker is offered (Octopus Tracker; E.ON Next Pulse Tracker); most suppliers do not have one. A 100% renewable option is credited to Octopus, OVO, E.ON Next, EDF, ScottishPower, Good Energy, So Energy and Ecotricity; Utility Warehouse and Fuse are not credited, consistent with their low disclosed fuel mix. Each supplier profile lists exactly which types we counted, so they can be checked and corrected.

Technology · 14%

Half of this area is app quality and half is the breadth of the supplier's ecosystem. App quality is the count-weighted mean Apple App Store rating across the supplier's official apps (companion apps included), rescaled from /5 to /10. Ecosystem is how many of five capabilities the supplier offers: an account and usage app, smart EV home charging, a public EV charging network or app, solar/battery/smart-home optimisation, and vehicle-to-grid (V2G). That count out of five is scaled to /10 and averaged with the app score. So a polished app with no charging or flexibility ecosystem scores below a supplier that has both. Google Play has no official ratings API, so it is left out for now and will be folded in when a reliable source exists.

Financial strength · 13%

An evidence-based composite drawn from public filings and ratings: parent or entity credit standing (Moody's, S&P or Fitch where rated), balance-sheet health, profitability and operating track record, mapped to a 0 to 10 score. It is a proxy for the risk of a supplier failing, which matters to customers because a collapse means a disruptive forced transfer to a new supplier, possibly onto a more expensive rate.

Sustainability · 10%

The disclosed renewable share of electricity from each supplier's own Ofgem-mandated Fuel Mix Disclosure (2024/25), divided by 10. It counts renewables only: nuclear is low-carbon but not renewable, so high-nuclear suppliers score lower here. This area is weighted lowest on purpose, because the disclosure is REGO-inclusive and a weak proxy for real environmental impact: a 100% renewable label can rest on cheap unbundled certificates rather than new generation. The nuclear and REGO-versus-owned-generation nuances are noted, not scored. The full explanation is in what are REGOs?

Price & value · coming soon

Paused, and not part of the score yet. A by-hand price comparison across every supplier and all 14 regional pricing zones, kept current often enough to be useful, is not sustainable with our current team size. It returns in February 2027 as an automated daily refresh, once the UK-wide tariff-sharing (REC) API goes live: each supplier's cheapest dual-fuel tariff will be measured against the Ofgem price cap and mapped to a 0 to 10 score, updated every day without manual work. Until then, compare current prices yourself before you switch. No tariff prices are published on this site in the meantime.