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Our latest results

Interim annual results 2023/24

Operational highlights

  • 49% reduction in customer complaints backlog; total complaints up 13%
  • 90% reduction in CRI
  • 6% reduction in leakage
  • 60% reduction in supply interruptions
  • Thames Tideway Tunnel on track for commissioning, the third phase of improvements that will increase the health of the river by reducing combined sewer overflows by c.95%
  • 10% increase in social tariff support for customers in vulnerable circumstances

Financial highlights

  • Underlying Revenue up 11% to £1.2 billion
  • Underlying EBITDA1 up 22% to £627 million
  • £1.0 billion invested in assets, a 30% year-on-year increase
  • £3.5 billion of committed liquidity2, underpinning our AMP7 investment programme

Refocused Turnaround Plan approved

  • New three-year turnaround plan to deliver a step change in performance
  • Six key operational priorities aligned to what our customers care about the most
  • Builds on the good progress and foundations laid in the last two years
  • Underpins delivery of our ambitious £18.7 billion PR24 business plan submitted to Ofwat 

Interim Co-CEOs, Cathryn Ross and Alastair Cochran said: 

“Today, we have announced a solid set of results with improvements in our key operational priorities and underlying financial performance in the first half. We’ve also invested a record £1 billion in the period to increase resilience in our network, improve customer service and environmental performance, and mitigate the impacts of climate change and population growth. 

“We have also submitted our business plan for 2025-30 to Ofwat as part of its PR24 price review and had our refocused Turnaround Plan approved by our Board. These plans build on what we have achieved over the last two years, and will deliver a turnaround in performance and step change in investment in the areas that matter most to our customers.

“Our shareholders support this much needed investment, underscoring their commitment to delivering Thames’ turnaround and life’s essential service for the benefit of our customers, communities, and the environment. At the same time, we recognise our customers are continuing to face cost-of-living challenges. We’ve therefore further increased our social tariff support in the first half of this year and our plans for the next regulatory period set out an expectation that we will provide over 530,000 households with meaningful support with their water bills.

“Turning around Thames will take time. We simply cannot do everything that our customers and stakeholders wish to see at a pace and for a price that everyone would like. We will continue to make the tough choices required to deliver what matters most to our customers and the environment. By being honest about what we can deliver and transparent about what we are doing, we believe we will build the trust and support we need from our customers and stakeholders if we are to succeed in our ambitious plans.


  1. Calculated excluding exceptional items
  2. As at 30 September 2023; excludes £550 million of additional undrawn liquidity facilities that can be drawn in limited circumstances

Interim results 2023/24

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