Complaint performance

We share information with household customers about how their water companies handle complaints each quarter. This data comes from complaints made directly to the water companies and those reported to us.

How we measure performance

For this quarterly complaints update, we use two sources to understand how companies are performing with complaints:

complaints received directly by the companies; and
complaints raised directly to CCW about the companies

This update focuses on the complaints performance for the current year, 2024-25.

How we compare performance

To compare companies of different sizes, we use a metric called ‘complaints per 10,000 connections’. This metric takes into account the number of water and wastewater connections each company serves.

For example, if Company A received 600 complaints and has 4,000,000 total connections, the calculation would be:

Complaints per 10,000 connections = 600/4,000,000 x 10,000 = 1.5

Comparative performance: we compare the performance of individual companies within their respective segments as either Water and Sewerage Companies (WaSCs) or Water Only Companies (WOCs).

Important note: the data in this publication is unaudited and a subject to change at the end of the year.

How we measure
Quartile 1 – Good
Quartile 2 – Better than median*
Quartile 3 – Worse than median*
Quartile 4 – Poor

*Median – a mid-point of the data set, or a middle value in the list of numbers that are arranged by highest to lowest.

Water and sewerage companies’ performance in 2024-25 (year to date)

Company	Household connections	Complaints to company	Per 10k (company)	Complaints to CCW	Per 10k (to CCW)
Anglian Water	3,082,287	5,779	18.75	231	0.75
Dŵr Cymru Welsh Water	1,498,832	4,310	28.76	181	1.21
Hafren Dyfrdwy	100,686	101	10.03	13	1.29
Northumbrian Water	1,266,440	2,146	16.95	39	0.31
Severn Trent Water	4,518,810	5,773	12.78	565	1.25
South West Water	1,022,599	3,606	35.26	146	1.43
Southern Water	2,077,571	6,372	30.67	314	1.51
Thames Water	5,979,736	31,577	52.81	1,405	2.35
United Utilities	3,371,871	11,391	33.78	398	1.18
Wessex Water	1,279,658	1,644	12.85	34	0.27
Yorkshire Water	2,388,813	10,703	44.80	501	2.10

Water only companies’ performance in 2024-25 (year to date)

Company	Household connections	Complaints to company	Per 10k (company)	Complaints to CCW	Per 10k (to CCW)
Affinity Water	1,508,900	4,062	26.92	231	1.70
Bristol Water	527,879	748	14.18	181	0.45
Cambridge Water	142,762	399	27.95	13	1.82
Essex & Suffolk Water	795,070	2,088	26.26	39	0.45
Portsmouth Water	310,725	552	17.76	565	0.26
SES Water	289,054	994	34.39	146	3.04
South East Water	1,014,859	2,320	22.86	314	1.00
South Staffs Water	574,646	1,137	19.79	1,405	1.11

Complaint trend

Below, you’ll find graphs that track how company complaint trends changed over time. First graph shows complaints received by company per 10,000 connections, while the other illustrates complaints reported directly to CCW per 10,000 connections.