The number of complaints made by households about water companies to the industry watchdog has risen by a record 84% in a year, driven by customer concern and confusion over rising bills.
The Consumer Council for Water (CCW) said the year-on-year increase was the highest in its 20-year history and showed "just how dissatisfied" many people were.
Total complaints to the watchdog rose to 15,115 in 2025-26, from 8,235 the previous year. Complaints made by households directly to water companies, which customers are required to do before approaching the CCW, rose by 56% to 321,347.
The top three subjects of complaints to the CCW were measured billing, affordability and billing administration.
Water customers in England and Wales have faced steep price rises in recent years, and the regulator Ofwat has allowed firms to increase bills by 36% between 2025 and 2030. Last month Ofwat approved bill increases for 13 companies to meet pressures on infrastructure and the environment; five of those had already been permitted to raise bills in 2024.
Mike Keil, chief executive of the CCW, said the figures "reflect just how dissatisfied many people still are with the state of the water sector", adding that customers are "impatient to see the benefits" of higher bills. "Companies need to be clear and open with their customers about how they are investing people's money to deliver real improvements," he said.
The CCW assessed each company on the number of complaints per 10,000 households served and on how much effort customers had to put in to get a complaint resolved. Thames Water and South West Water were rated "poor" on both measures. Portsmouth Water and Bristol Water were the only companies to score "good" on both, retaining their place at the top of the rankings.
David Bird, retail director at Thames, apologised to customers who "have not received the service they should expect". He said: "We know bill clarity has been a particular source of frustration, which is why we have launched a programme to redesign them, so they are easier to understand." Bills for the average Thames customer rose by 31% in 2024 and by 3.4% this year.
A spokesperson for the industry body Water UK said: "We understand increasing bills is never welcome, but the money is needed to fund vital upgrades to secure our water supplies, support economic growth and end sewage entering our rivers and seas." The spokesperson added that 94% of complaints are "being dealt with at the earliest possible stage without the need for further involvement from the consumer body".
That last figure is the one worth holding up to the light, because it is doing something quietly remarkable. Of the 321,347 complaints made directly to water companies, 15,115 went on to the watchdog. That is roughly five in every hundred.
So the industry's 94% is, near enough, the proportion of complaints that did not escalate: the watchdog received 4.7% of them. The Questionable Times' analysts observe that this is a measurement of stopping. It would look exactly the same if every one of those complaints had been resolved to the customer's complete satisfaction, and exactly the same if the customer had simply run out of afternoons.
The Department of Unnecessary Research therefore records the sector's performance indicator as a tautology in good standing: complaints that end are complaints that have ended. On this measure the finest water company in Britain would be one whose customers, in the fullness of time, stopped contacting it at all.