The UK water industry plays a crucial role in daily life, delivering clean, safe water to homes and businesses across the country. Choosing the right water supplier is important for ensuring quality service, affordability, and environmental responsibility.
This guide explores the top 10 water companies in the UK, offering insights into their strengths, areas served, and performance metrics to help both domestic and commercial users make informed decisions.
What Role Do Water Companies Play in the UK?
Water companies in the UK are responsible for sourcing, treating, and distributing fresh water, as well as collecting and treating wastewater.
They ensure that clean, safe water reaches households and businesses daily while managing sewage to protect public health and the environment.
These companies maintain infrastructure such as pipes, reservoirs, and pumping stations, and must comply with strict regulations on water quality, customer service, and environmental performance. They also work to reduce water leakage, manage droughts and floods, and support sustainability initiatives.
- Deliver water supply and sewage services
- Ensure water quality meets health standards
- Maintain vast water infrastructure networks
Overall, UK water companies play a crucial role in safeguarding public health, supporting the environment, and ensuring a reliable water supply for everyone.
How Is Water Supplied and Regulated Across the UK?
Water supply in the UK involves a structured process from collection to distribution. The sector is highly regulated to ensure transparency, efficiency, and safety.
Water Sourcing and Treatment
Water is sourced from rivers, reservoirs, lakes, and underground aquifers. It is then treated through filtration and disinfection processes before it is safe for consumption.
Distribution and Infrastructure
Once treated, the water is pumped through a complex pipe network to reach households and businesses. Companies are responsible for maintaining this infrastructure to prevent leaks and service interruptions.
Regulatory Bodies and Oversight
Ofwat regulates economic performance, while the Drinking Water Inspectorate (DWI) ensures safety and quality standards. The Environment Agency monitors how companies manage resources and pollution.
Why Should Businesses and Households Compare Water Suppliers?
Choosing the right water supplier can lead to better service quality and potential cost savings. Since the business water market in England was deregulated in 2017, commercial customers have the freedom to switch suppliers.
For households, even though supplier choice is limited based on region, understanding provider performance helps in knowing what to expect in terms of service reliability, billing transparency, and complaint resolution.
Benefits of comparing water suppliers:
- Cost Efficiency: Competitive pricing for businesses
- Service Reliability: Reduced risk of disruptions and leaks
- Environmental Responsibility: Support sustainable water companies
- Customer Service: Better support and complaint handling
Comparing suppliers helps in making informed decisions that align with usage needs and environmental values.
What Should You Look for in a Reliable Water Supplier?
Not all water suppliers perform at the same level. Evaluating key features helps in identifying the most suitable provider for individual or business needs.
Key factors to consider when choosing a water supplier:
- Service Area Coverage: Ensure the supplier operates in your region
- Customer Satisfaction: Look at reviews and complaint data
- Environmental Commitment: Ratings and sustainability efforts
- Billing and Tariffs: Transparent and flexible payment plans
- Leak Detection Services: Proactive infrastructure maintenance
Water suppliers that demonstrate consistent service, strong ethical practices, and user-friendly billing options offer long-term reliability and peace of mind.
How Does the UK’s Water Market Differ for Businesses and Domestic Users?
The UK’s water market operates differently for business users and domestic customers, especially in England where non-household users can choose their supplier.
| Criteria | Business Users | Domestic Users |
| Supplier Choice | Can switch suppliers | Fixed by region |
| Billing | Customised contracts | Standardised tariffs |
| Regulation | Ofwat regulates competitive market | Ofwat monitors but no switching |
| Flexibility | Greater pricing and service flexibility | Limited options |
| Availability | England only | UK-wide but no switching |
This distinction creates a competitive landscape for businesses to optimise costs, while households rely on regional suppliers bound by strict performance standards.
Who Are the Top 10 Water Companies in UK?
The UK water sector includes a mix of large-scale regional suppliers and specialist providers. Below are the leading water companies ranked by size, service quality, and environmental performance.
1. Thames Water
Thames Water is the UK’s largest water and wastewater service provider, supplying clean water to over 16 million customers across London and the Thames Valley.
The company plays a vital role in delivering essential services while managing one of the most complex water networks in the country.
In response to increasing drought risks, Thames Water has introduced hosepipe restrictions in specific areas to help preserve resources. Customers are also encouraged to adopt water-saving habits, with the company offering helpful tips and guidance.
Who Are They?
Thames Water Utilities Limited operates across a broad region of southern England, supporting both homes and businesses.
Headquartered in Reading, the company employs a large workforce dedicated to ensuring water safety, quality, and sustainability. It provides 24/7 customer support and digital account management.
What They Do?
The company supplies over 2.6 billion litres of water per day, treats sewage, manages wastewater, and maintains a vast infrastructure of pipes and treatment facilities. Services include leak detection, billing support, and the Priority Services Register for vulnerable customers.
Why Choose Them?
Thames Water continues to invest in leak prevention, drought resilience, and customer service improvements. It offers:
- Flexible billing and support
- Water-saving tools and advice
- Wide regional coverage with reliable supply
Its commitment to infrastructure upgrades and sustainability makes it a key player in the UK’s water industry.
2. Severn Trent Water
Severn Trent Water serves more than 4.6 million households and businesses across the Midlands and parts of Wales. It is one of the UK’s most trusted water suppliers, known for environmental performance, excellent customer service, and infrastructure investments.
Following a dry summer, Severn Trent has encouraged water-saving habits and continues to upgrade its systems for long-term resilience. It actively engages with communities, promoting sustainability and education.
Who Are They?
Headquartered in Coventry, Severn Trent is a major FTSE 100 listed utility company. It delivers clean water and manages wastewater for millions of customers, while also supporting local communities and nature projects.
The company runs award-winning public programmes and offers recreational spaces like reservoirs for public enjoyment.
What They Do
Severn Trent handles water supply, wastewater treatment, billing services, and maintenance of thousands of kilometres of pipelines. It also provides support to vulnerable customers and promotes responsible water use.
Why Choose Them?
Customers choose Severn Trent for reliability, sustainability, and community focus. It offers:
| Feature | Benefit |
| Environmental Rating | 4-Star (Top in the UK) |
| Water-Saving Programmes | Yes |
| Priority Services | Available for vulnerable customers |
| Billing Support | Flexible plans and help available |
| Community Engagement | Strong focus through events and education |
With a strong environmental reputation and customer-first approach, Severn Trent is a leading choice in the UK.
3. United Utilities
United Utilities is the largest listed water company in the UK, supplying water and wastewater services to around 7 million customers in North West England. The company plays a critical role in maintaining public health and environmental protection through advanced infrastructure and water management systems.
It focuses on sustainability, investing in water-saving technology and customer support initiatives to improve affordability and reliability across the region.
Who Are They?
Founded in 1995, United Utilities is headquartered in Warrington and serves both urban and rural communities. It is known for its proactive investment in modern infrastructure and its leadership in digital customer services, including paperless billing and online account management.
What They Do?
The company collects water from rivers, reservoirs, and boreholes, treats it at its plants, and distributes it to homes and businesses. It also removes and treats wastewater through an extensive sewerage system before returning clean water to the environment.
Services include:
- Water supply and treatment
- Wastewater collection and recycling
- Leak detection and repair
- Billing and account support
Why Choose Them?
United Utilities offers:
- Efficient digital services
- Financial support options like WaterSure
- Free water-saving gadgets
- Strong environmental and community focus
Its combination of scale, innovation, and customer care makes it a reliable provider in the North West.
4. Northumbrian Water
Northumbrian Water provides water and sewerage services to around 2.7 million people across Northumberland, Tyne and Wear, Durham, and parts of North Yorkshire. The company is recognised for its sustainability leadership, innovative energy use, and community engagement.
With a strong ethical focus and clear sustainability goals, Northumbrian Water is working towards achieving Net Zero by 2027, making it one of the most environmentally conscious providers in the UK.
Who Are They?
Operating under Northumbrian Water Group, the company also includes Essex and Suffolk Water. It is privately owned and headquartered in Durham, serving both urban and rural communities with a focus on ethical operations and customer support.
What They Do
The company supplies clean water, treats wastewater, and generates renewable energy from waste. It invests in smart metering, offers help with bills, and manages extensive assets to ensure long-term reliability and safety.
Why Choose Them?
Northumbrian Water stands out for:
- Ethical operations and sustainability
- Support for vulnerable customers
- Community programmes promoting education and skills
- Advanced leak detection and renewable energy use
Its commitment to environmental protection and future-focused planning makes it a top choice in the North East.
5. Yorkshire Water
Yorkshire Water provides essential water and wastewater services to over 5 million customers and 140,000 businesses across the Yorkshire region.
The company is focused on reliability, infrastructure resilience, and protecting the environment through responsible water and wastewater management.
It operates across a diverse landscape, managing daily supply while preparing for challenges like climate change and population growth.
Who Are They?
Yorkshire Water operates across urban centres and rural communities, sourcing water from reservoirs, rivers, and groundwater. Headquartered in Bradford, it is committed to delivering affordable services while maintaining strong community ties.
The company also engages in open data partnerships to promote transparency and innovation in the sector.
What They Do
Yorkshire Water collects and treats up to 1.5 billion litres of water daily, manages sewerage systems, and invests in river health projects. It also provides household support services, including help with bills, priority assistance, and education on water-saving habits.
Why Choose Them?
| Feature | Details |
| Water Supplied Daily | 1.2 to 1.5 billion litres |
| Business Customers | 140,000 served |
| Environmental Initiatives | Strong river health and land care |
| Innovation | Smart metering and infrastructure upgrades |
| Customer Support | Priority Services and flexible billing |
Yorkshire Water blends large-scale service with a personal, community-centred approach, making it a trusted name across the region.
6. Anglian Water
Anglian Water provides essential water and wastewater services to over six million customers in the East of England and Hartlepool. The company is deeply committed to sustainability, aiming to become net zero by 2030 while improving service reliability through innovation.
Its approach, known as “Love Every Drop,” focuses on environmental stewardship, community support, and long-term infrastructure planning.
With strong customer service and active conservation programmes, Anglian Water stands out for its ethical and practical delivery.
Who Are They?
Anglian Water is a private utility company operating across one of the driest regions in the UK. Its focus is on long-term water security, reducing leaks, and protecting ecosystems like chalk streams and rivers. It also supports customers with billing queries, live chat, and priority services.
What They Do?
The company supplies clean drinking water sourced from rivers, reservoirs, and underground aquifers. It maintains thousands of kilometres of water mains and public sewers, investing in smart meters and pipe renewal.
Services include:
- Water and wastewater treatment
- Leak detection and repairs
- Financial support and Priority Services
- Pollution reporting and community education
Why Choose Them?
Anglian Water is known for:
- Climate-focused policies
- Local area support teams
- Community programmes and school education
- Strong response to leaks and environmental issues
It’s an ideal choice for those valuing sustainability and customer care in a water supplier.
7. Scottish Water
Scottish Water delivers water and wastewater services to more than 5 million people across Scotland. As a publicly owned utility, it reinvests all profits into improving infrastructure and services, rather than paying private shareholders.
The company is widely respected for its environmental commitment, customer care, and major investment into upgrading assets to meet future challenges such as climate change and aging infrastructure.
Who Are They?
Scottish Water is Scotland’s national water provider, operating over 30,000 miles of pipes, 2,000 treatment plants, and thousands of reservoirs and sewers. It is accountable to the Scottish Government and the public, ensuring transparent and responsible management.
What They Do?
The company supplies clean drinking water and treats wastewater across homes and businesses. It operates large-scale projects focused on:
- Reducing carbon emissions
- Improving flood defences
- Monitoring storm overflows and quality of rivers
It also invests £600 million annually in infrastructure to meet growing demands and climate-related stress.
Why Choose Them?
As a public service provider, Scottish Water offers:
- Not-for-profit operations
- Comprehensive customer support
- Infrastructure investment for long-term security
- Programmes for environmental protection and climate resilience
Its public ownership and environmental focus make it a standout in the UK water sector.
8. South West Water
South West Water serves approximately 1.8 million customers across Devon, Cornwall, the Isles of Scilly, and parts of Somerset and Dorset. The company is part of the Pennon Group and focuses on clean water supply, wastewater treatment, and environmental improvement.
South West Water is also known for community support, especially for those facing water poverty, and works on modernising its network to cope with future demands.
Who Are They?
Based in Exeter, South West Water manages thousands of miles of pipes and treatment facilities across the South West. It provides essential public services while investing in technology, sustainability, and customer communication.
What They Do?
South West Water collects water from local sources, treats it, and distributes it for household and business use. It also:
- Maintains 11,000+ miles of pipes
- Treats wastewater before discharge
- Offers financial and Priority Services
- Supports local education and wellbeing programme
Why Choose Them?
| Key Feature | Details |
| Customer Coverage | 1.8 million across the South West |
| Parent Company | Part of Pennon Group |
| WaterShare+ | Customers can be shareholders |
| Environment | Storm overflow monitoring and updates |
| Community Focus | Support for hardship and local initiatives |
South West Water is ideal for customers who want a local, community-focused provider with strong investment in the environment.
9. Southern Water
Southern Water provides water supply and wastewater services to over two million customers across Kent, Sussex, Hampshire, and the Isle of Wight.
With a large and complex network, the company focuses on building a resilient water future amid rising climate challenges. It also helps customers manage rising bills through financial support and transparent communication.
Who Are They?
Southern Water operates one of the largest networks in the South East, covering urban and rural areas alike. Its Control Centre monitors operations 24/7, ensuring supply stability and immediate response to incidents.
What They Do?
The company sources water from rivers, reservoirs, and aquifers and treats wastewater through a vast sewer system. Key services include:
- Drinking water supply
- Sewage treatment and recycling
- Customer billing and meter reading support
- Environmental monitoring and investment
Why Choose Them?
Southern Water offers:
- Real-time updates on storm overflows
- Financial aid for households in need
- Automated Meter Reading (AMR) tech
- Planning for future water scarcity and population growth
It’s a forward-focused company that aims to deliver stability and sustainability under increased pressure.
10. Wessex Water
Wessex Water delivers clean water to 1.4 million people and manages wastewater services for 2.9 million across the South West of England. Known for its high customer service ratings, it focuses on quality, environmental care, and modern infrastructure.
The company promotes sustainability, carbon neutrality, and community partnerships to meet both local and environmental needs.
Who Are They?
Wessex Water is based in Bath and operates across Dorset, Somerset, Bristol, Wiltshire, and Gloucestershire. It is owned by the Malaysian investment company YTL Corporation, but retains a strong regional identity and customer-first approach.
What They Do?
The company supplies water from deep boreholes and treats wastewater using advanced technologies. Services include:
- Online billing and account management
- Priority Services for vulnerable customers
- Meter reading assistance and storm monitoring
- Customer-led community initiatives and transparency tools
Why Choose Them?
| Feature | Detail |
| Region | South West (Dorset, Somerset, Bristol) |
| Environmental Focus | Net environmental gain + carbon neutrality |
| Technology Use | Storm overflow maps, AMR meters |
| Customer Support | Highly rated services and flexible payment |
| Community Investment | Education, biodiversity, and outreach |
Wessex Water stands out for innovation, customer satisfaction, and long-term environmental commitment.
Comparison Table of the Top 10 Water Companies in the UK
| Water Company | Region Served | Ownership | Environmental Commitment | Customer Support Services | Special Programmes |
| Thames Water | London, Thames Valley | Private | Leakage reduction, drought alerts | Priority Services, online billing | “Bin it – don’t block it”, water saving |
| Severn Trent | Midlands, Wales | Private (FTSE 100) | 4-Star environmental rating | Billing help, Priority Services | River Positive, WaterAid partnership |
| United Utilities | North West England | Private (Listed) | Carbon reduction, green initiatives | WaterSure, digital tools | Free water-saving gadgets, education |
| Northumbrian Water | North East England, Essex & Suffolk | Private | Net Zero by 2027, renewable energy use | Bill support, smart meters | School programmes, Gas-to-Grid plant |
| Yorkshire Water | Yorkshire region | Private | River protection, open data strategy | Flexible billing, Priority Services | Environmental innovation, community events |
| Anglian Water | East of England, Hartlepool | Private | Net Zero by 2030, chalk stream projects | Leak detection, live chat support | “Love Every Drop”, school programmes |
| Scottish Water | Entire Scotland | Publicly Owned | Net Zero goal, £600m annual investment | Full customer transparency | Annual Consultative Meetings, education |
| South West Water | Devon, Cornwall, Dorset, Somerset, Scilly | Private (Pennon Group) | Storm overflow monitoring, AI research | WaterShare+, financial support | Better Futures Fund, WaterFit Live |
| Southern Water | South East England (Kent, Sussex, Hants) | Private | Drought resilience, AMR meters | Online help, bill support | Regional upgrades, storm tracking |
| Wessex Water | South West (Dorset, Somerset, Bristol) | Private (YTL Corp) | Carbon neutral by 2030, storm data maps | Top-rated support, online access | Target 20 challenge, biodiversity funding |
Conclusion
Choosing the right water company is essential for ensuring consistent service, competitive pricing, and a positive environmental impact.
Whether you’re a homeowner or a business user, understanding the strengths of the UK’s top water suppliers can help you make smarter decisions. Review your provider’s performance regularly and explore options to optimise your water service.
Frequently Asked Questions
What’s the difference between a water supplier and a water wholesaler in the UK?
A water supplier handles customer accounts and billing. A wholesaler is responsible for sourcing, treating, and transporting water.
Can businesses in the UK switch water suppliers like they do with energy?
Yes, businesses in England can switch suppliers under the deregulated water market. This allows them to find better rates and services.
How are water rates calculated for commercial properties?
Rates are based on volume of usage, service types, and regional tariffs. Some companies offer tailored plans for businesses.
Are there independent water providers outside the main regional suppliers?
Yes, some independent suppliers exist, especially in the business sector. They often operate using networks maintained by larger water wholesalers.
How do water companies in the UK handle environmental sustainability?
Many companies invest in green infrastructure and water-saving initiatives. Some also aim for carbon neutrality and pollution reduction.
What is the role of Ofwat in regulating UK water companies?
Ofwat monitors company performance, pricing, and customer service. It ensures fairness and transparency in the water sector.
Do water companies in the UK offer leak detection and repair services?
Yes, most suppliers have active leak detection programs. Some offer free or subsidised repairs for domestic and business users.
