Executive summary
The 2026 Supplier Performance Report ranks the UK's major domestic energy suppliers on the six consumer-impact dimensions used across PowerGuardian: complaint performance, tariff competitiveness, customer service, direct-debit fairness, consumer transparency and market stability. Every score is derived from published complaints data, independent service metrics and PowerGuardian's own tariff monitoring — with no commission or supplier funding influencing the results.
This year the gap between the best and worst performers widened. A small group of suppliers combined competitive fixed tariffs with strong service, while several large incumbents continued to lag on complaint handling despite price stability across the market.
Key findings
- The top three suppliers resolved over 90% of complaints within eight weeks, more than double the rate of the bottom quartile.
- Billing accuracy and direct-debit fairness remain the biggest drivers of customer dissatisfaction, ahead of price.
- Fixed tariffs from mid-size suppliers frequently beat the price cap by £80–£160 a year for typical usage.
- Smaller, specialist suppliers scored highest on service but offered a narrower range of tariffs.
How suppliers were scored
Each supplier is scored across the same six weighted dimensions used on the PowerGuardian Supplier Monitor: complaint performance (25%), tariff competitiveness (20%), customer service (20%), direct-debit fairness (15%), consumer transparency (10%) and market stability (10%). Scores are normalised to a 0–100 scale so suppliers of different sizes can be compared fairly.
We deliberately weight complaint performance and tariff competitiveness most heavily because these are the areas where households feel the impact of a poor supplier most directly — through unresolved issues or higher bills.
What separates the best from the rest
The strongest performers share three traits: transparent tariffs without hidden exit penalties, accurate and fair direct-debit handling, and fast complaint resolution. Where a supplier scored poorly, it was almost always because of slow or unresolved complaints rather than headline price.
For most households, switching from a bottom-quartile supplier to a top-quartile one improves both cost and experience — the two are not a trade-off.
Data & charts
Explore the key figures behind this report. Charts and tables are interactive — hover, sort and compare.
Overall supplier performance score
Weighted 0–100 score across the six PowerGuardian dimensions, loaded from the same canonical dataset as the Supplier Monitor.
- Overall score
Source: PowerGuardian 2026 Supplier Performance Report
Score breakdown by dimension
How the leading suppliers score on each weighted dimension. Sort by any column.
| Octopus Energy | 87 | 99 | 94 | 83 | 100 | 87 | 92 |
| So Energy | 79 | 80 | 84 | 74 | 78 | 73 | 79 |
| EDF Energy | 70 | 81 | 73 | 68 | 70 | 79 | 73 |
| OVO Energy | 59 | 67 | 59 | 61 | 64 | 71 | 63 |
| Utility Warehouse | 62 | 54 | 67 | 58 | 59 | 71 | 61 |
| E.ON Next | 51 | 75 | 57 | 48 | 63 | 71 | 60 |
| British Gas | 50 | 55 | 52 | 52 | 57 | 78 | 55 |
| Co-op Energy | 48 | 50 | 51 | 51 | 58 | 60 | 52 |
| ScottishPower | 41 | 57 | 46 | 44 | 53 | 71 | 50 |
Source: PowerGuardian 2026 Supplier Performance Report
Methodology
- Data period: 1 January 2026 – 30 June 2026 (H1 2026). Score snapshot taken on 10 July 2026 and republished on the same date as the live Supplier Monitor.
- Complaints (25%): Ofgem Domestic Complaints Data, Q1 and Q2 2026 quarterly releases — complaints per 100,000 customers and % resolved within 8 weeks.
- Customer service (20%): Citizens Advice Star Rating, Q1 and Q2 2026 releases — call wait times, email response, easy-to-contact and complaint-handling components.
- Tariff competitiveness (20%): PowerGuardian weekly tariff monitor (Jan–Jun 2026), scored against Ofgem Typical Domestic Consumption Values 2026 and the Ofgem Default Tariff Cap for July–September 2026 (£1,862).
- Direct-debit fairness (15%): PowerGuardian direct-debit audit (June 2026) covering credit balances, review cadence and unexplained increases, cross-checked against Ofgem's Standards of Conduct.
- Transparency (10%): audit of published tariff information, exit fees and standing-charge disclosure on each supplier's site during June 2026.
- Market stability (10%): Ofgem financial resilience updates and supplier customer-base movement over the previous 12 months.
- Each dimension is normalised to 0–100, combined using the fixed weights above (the same weighting used on the Supplier Monitor) and rounded to a whole number. Every figure in this report — and the calculation sheet behind each score — is published as a downloadable CSV above. No supplier can pay to change its score.
Downloadable data & scoring tables
The raw calculation sheet behind every score in this report — free to download and re-use with attribution.
Sources & references
- Ofgem — Energy price cap — UK regulator's quarterly price cap announcements
- Citizens Advice — Energy supplier comparison — Independent supplier guidance & complaints data
- Ofgem — Typical Domestic Consumption Values — Standard usage assumptions for UK households
Figures are checked against primary sources before publication. See our methodology for details.
Editorial note
PowerGuardian publishes independent, UK-focused research, analysis and commentary on household energy costs. Confirmed data, our own estimates, forecasts and scenarios are labelled separately so you can see which is which.
This report is reviewed at each Ofgem price cap announcement and whenever a source dataset it relies on is revised. It was last reviewed on 24 August 2026.
We take no commission from energy suppliers for the rankings, scores or figures shown here.
Read our editorial policy and corrections policy.
