What Is complain.report?
complain.report is an independent service that aggregates complaint statistics from UK financial and utility regulators. We do not receive any payment from the companies we rank, and we do not accept sponsored placements in our rankings.
Our goal is simple: make it easy for UK consumers to see which banks, energy suppliers, broadband providers and insurers attract the most complaints — before they sign up, and before they decide whether to escalate a dispute.
Our Data Sources
Financial Conduct Authority (FCA) — Banks & Insurers
The FCA requires all regulated firms to publish complaint data twice yearly (H1: January–June, H2: July–December). The dataset includes complaint volumes broken down by product type (current accounts, mortgages, credit cards, home insurance, etc.) and is published at firm level. Rates are expressed as complaints per 1,000 accounts or policies, enabling size-adjusted comparisons. Source: fca.org.uk/data/complaints-data
Ofgem — Energy Suppliers
Ofgem publishes quarterly complaint data for domestic gas and electricity suppliers. The dataset covers complaint volumes per 100,000 customers, resolution timescales, and the proportion of complaints resolved on the same day or within eight weeks. We use the per-100,000-customer rate as our primary metric. Source: ofgem.gov.uk
Ofcom — Broadband & Phone Providers
Ofcom publishes quarterly complaints data covering broadband, landline, pay-monthly mobile and pay-TV services. Rates are expressed per 100,000 subscribers. We use broadband complaints as the primary metric for broadband providers. Source: ofcom.org.uk
Financial Ombudsman Service
The Financial Ombudsman Service (FOS) publishes firm-level data showing how many complaints were escalated and the percentage upheld in the customer's favour. A high uphold rate indicates that not only are customers complaining — their complaints are judged to be justified. We display this alongside FCA complaint rates for banks and insurers. Source: financial-ombudsman.org.uk
How We Calculate Scores
Each company receives a rating from 1 (Excellent) to 5 (Terrible) based on where their complaint rate falls within the distribution of all companies in the same sector. We use percentile rankings rather than fixed thresholds, so the scores are relative to peers in the same sector.
| Rating | Label | Percentile Range | Meaning |
|---|---|---|---|
| 1 | Excellent | Bottom 20% (fewest complaints) | Among the best performers in the sector |
| 2 | Good | 20th–40th percentile | Better than average for the sector |
| 3 | Average | 40th–60th percentile | Typical performance for the sector |
| 4 | Poor | 60th–80th percentile | Worse than average; complaints are elevated |
| 5 | Terrible | Top 20% (most complaints) | Among the worst performers in the sector |
Scores are calculated independently for each sector. A rating of 3 (Average) for a bank cannot be directly compared to a rating of 3 for an energy supplier — the underlying rates and customer bases differ significantly.
Update Schedule
FCA (banks and insurers): Published twice yearly, typically in August (H1 data: January–June) and February (H2 data: July–December). We update bank and insurance scores within two weeks of each publication.
Ofgem (energy suppliers): Published quarterly, approximately six weeks after each quarter ends. We update energy scores after each quarterly release.
Ofcom (broadband providers): Published quarterly, typically two months after each quarter ends. We update broadband scores after each quarterly release.
Financial Ombudsman: Published quarterly and annually. Uphold rates are updated when new data becomes available.
Company Name Matching
Large financial groups often operate multiple brands under a single regulated entity. For example, Halifax and Bank of Scotland are both part of Lloyds Banking Group. Where regulator data is published at group level rather than brand level, we attribute it to the parent group and note the relationship on individual brand pages.
When a group operates significantly different brands targeting different customer segments, and where the regulator publishes separate data, we display them separately. We aim to be transparent about any grouping decisions on individual company pages.
Limitations
Formal complaints only: Our data covers formal complaints registered with the company and, where applicable, escalated to an Ombudsman. Informal complaints, social media grievances, and customers who gave up without complaining are not captured. The true level of customer dissatisfaction may be higher than the official data suggests.
Reporting thresholds: The FCA requires firms to report complaint data only if they receive 500 or more complaints in a six-month period, or if they have 10,000 or more accounts. Smaller firms may fall below these thresholds and therefore not appear in our data, even if their complaint performance is poor.
Cross-sector comparisons: Complaint rates use different bases across sectors (per 1,000 accounts for banks/insurers; per 100,000 customers for energy/broadband). Do not directly compare a bank's rate to an energy supplier's rate — the figures are not directly comparable.
Product mix effects: Some companies specialise in higher-risk or more complex products that inherently attract more complaints. A high complaint rate does not always mean poor service — context matters when interpreting the data.
Contact
Found an error in our data? Have a question about our methodology? We welcome corrections and feedback. Data accuracy is important to us — if you spot something wrong, please get in touch.