Five water companies have been handed a partial victory in their battle against regulator Ofwat, with customers of Anglian Water, Northumbrian Water, South East Water, Southern Water and Wessex Water seeing bills rise by an average of 2.2% more than already announced.
The Competition and Markets Authority rejected 83% of the additional revenue the companies had sought.
Anglian, Northumbrian, South East, Southern and Wessex had each challenged Ofwat's December 2024 price control decision, which already set out average bill increases of 36% over the five years to 2030, arguing the settlement left them unable to meet their regulatory obligations.
The CMA's independent panel allowed an additional £463 million in revenue across the five companies, down from the £556 million it had provisionally proposed in October and well short of the £2.7 billion the companies had requested.
Panel chair Kirstin Baker said the extra money reflected "genuine need" while rejecting the bulk of what companies sought.
A significant portion of the additional allowance reflects higher financing costs since Ofwat's original decision rather than new spending commitments, with the remainder tied to specific environmental and infrastructure obligations.
Southern Water customers face the steepest bills, at £641 a year on average, while Northumbrian Water customers will see no change from Ofwat's original decision.
The CMA's full report will be published in a minimum of two weeks following a formal process involving Ofwat and the Department for Environment, Food and Rural Affairs.
None of the five companies in the CMA ruling are listed in London. Northumbrian Water is 75% owned by CK Hutchison Holdings, a Hong Kong-based conglomerate, with the remaining 25% held by US private equity firm KKR. Wessex Water is fully owned by YTL, a Malaysian corporation. South East Water is half owned by an Australian infrastructure fund, 25% by a Canadian private company and 25% by the NatWest pension fund. Southern Water's largest stakeholder is Australian firm Macquarie, which holds around 62%. Anglian Water's parent AWG was previously listed on the LSE and was a member of the FTSE 250, but is now privately owned by the Osprey Consortium.