Water is one of London’s most vital resources, serving millions of residents and businesses every single day. Behind the taps and flowing pipelines are water companies that ensure every drop is clean, safe, and reliable. From drinking water to wastewater treatment and commercial water management, these companies keep the city functioning smoothly.
For those wondering which suppliers operate in London, this guide highlights the top 10 water companies in London, their services, water quality, and how they cater to both households and businesses.
What Are the Leading Water Companies in London?
London’s water system operates under a combination of local supply companies and licensed business water retailers. Most households receive their water from Thames Water, which dominates the city’s supply, while businesses can choose from multiple competitive retailers.
Water companies in the city perform three primary roles:
Water Supply and Distribution
Residential and commercial users rely on a consistent supply of drinking water. Companies like Thames Water and Affinity Water are responsible for sourcing, treating, and delivering water to London homes.
Wastewater and Sewerage Services
Wastewater treatment is a crucial responsibility. Companies handle the safe collection, treatment, and disposal of used water to maintain hygiene and protect the environment.
Business Water Services
While households stick to the default supplier, businesses can choose water retailers that provide tailored solutions like metering, usage reports, and efficiency plans. This competitive market allows companies to save costs and adopt sustainable water practices.
Who Are the Top 10 Water Companies in London?
1. Thames Water – “London’s Largest Water Lifeline”
Thames Water is not only London’s biggest water provider but also the backbone of the city’s water infrastructure. Established in the 1800s, it now serves over 15 million customers across London and the Thames Valley.
Its responsibilities go beyond supplying drinking water it also manages wastewater collection, sewage treatment, and the city’s extensive network of pipes and reservoirs.
The company has made significant investments in sustainability, including the reduction of water leaks, upgrading treatment facilities, and planning for population growth.
Thames Water also actively participates in educational and environmental initiatives, encouraging residents to use water wisely. For businesses, it ensures reliable supply and emergency response services, making it the primary go-to provider for the capital.
Specialized Role
Full-scale residential and commercial water supply with integrated wastewater management.
Perfect For
Households, large commercial properties, and institutions requiring robust service coverage.
Pricing: Regulated residential rates; business rates vary by usage and service.
- Website: www.thameswater.co.uk
- Phone: 0800 316 9800
- Address: Clearwater Court, Vastern Road, Reading, RG1 8DB
- Email: customer.help@thameswater.co.uk
Review: ★★★★☆ “Dependable and professional service with prompt updates during maintenance.”
2. Affinity Water – “Supplying the North and West”
Affinity Water provides clean drinking water to North and West London, serving approximately 3.8 million people. The company has a strong focus on sustainability, frequently running campaigns to reduce leakage and encourage water conservation. Affinity Water also collaborates with local communities, educating residents about efficient water use.
Unlike some suppliers, it takes pride in minimal disruption services, using smart technology to monitor water pressure and detect early leakages. Affinity Water’s long-term strategy focuses on protecting rivers, wetlands, and groundwater sources, ensuring a sustainable supply for future generations.
Specialist Focus
Eco-friendly water supply with emphasis on conservation and leak prevention.
Most Suitable For
Households and small businesses in North and West London prioritizing sustainable water.
Pricing: Regulated for households; commercial tariffs on request.
- Website: www.affinitywater.co.uk
- Phone: 0345 357 2406
- Address: Tamblin Way, Hatfield, AL10 9EZ
- Email: customer.services@affinitywater.co.uk
Review: ★★★★☆ “Reliable service and great community programs for water conservation.”
3. SES Water – “Trusted Supplier in the South”
SES Water focuses on South London and surrounding towns, ensuring a stable supply of drinking water for homes and small businesses. The company is recognized for its reliable service, regular upkeep of local infrastructure, and active involvement in community initiatives.
SES Water also leads local educational initiatives about water saving and invests in modern infrastructure to minimize disruptions during repairs or upgrades. For businesses, it ensures straightforward billing and support, making it ideal for small-scale operations.
Special Role
Maintaining uninterrupted residential water service with local expertise.
Optimal Users
Residents and SMEs in South London requiring consistent water supply.
Pricing: Fixed residential rates; business rates via retailers.
- Website: www.seswater.co.uk
- Phone: 01737 772000
- Address: London Road, Redhill, RH1 1LJ
- Email: support@seswater.co.uk
Review: ★★★★☆ “Excellent for reliability and rapid response to service requests.”
4. South East Water – “Delivering Quality to the Suburbs”
South East Water serves the suburban fringes of London, supplying water to residential and light commercial customers. They are well-regarded for their water quality, meeting all UK drinking water standards, and actively investing in pipelines and treatment plants.
The company offers local initiatives to reduce wastage and frequently communicates with residents about planned work, which helps minimize inconvenience during upgrades. It is especially suited for suburban and rural-urban areas, where it manages water demand efficiently.
Expert Area
High-quality water supply with a strong focus on local network upgrades.
Ideal Consumers
Ideal for suburban homes and small businesses that require consistent access to clean, dependable water.
Pricing: Based on standard usage; business pricing through approved retailers.
- Website: www.southeastwater.co.uk
- Phone: 0333 000 0001
- Address: Rocfort Road, Snodland, Kent, ME6 5AH
- Email: info@southeastwater.co.uk
Review: ★★★★☆ “Clear communication, reliable water quality, and great local support.”
5. Essex & Suffolk Water – “East London’s Reliable Partner”
Serving East London and nearby regions, Essex & Suffolk Water is part of Northumbrian Water Group. The company supplies millions of liters of high-quality water daily, with a reputation for strong environmental responsibility.
It invests in upgrading pipelines and protecting water sources, ensuring long-term sustainability. For residential and small business customers, the company emphasizes transparency in billing and service updates.
Focus Area
Safe and sustainable water delivery with proactive environmental care.
Recommended For
East London homes and businesses needing consistent and eco-conscious service.
Pricing: Standard residential; business rates vary by consumption.
- Website: www.eswater.co.uk
- Phone: 0345 782 0999
- Address: Northumbria House, Abbey Road, Pity Me, DH1 5FJ
- Email: info@eswater.co.uk
Review: ★★★★☆ Known for uninterrupted water service and responsive, customer-focused support.
6. Veolia Water UK – “Innovative Commercial Water Solutions”
Veolia Water UK is a global environmental solutions provider with a strong presence in London’s commercial and industrial water sector. Unlike traditional suppliers focused on households, Veolia specializes in wastewater treatment, water recycling, and industrial water management.
The company works with factories, hospitals, and large facilities to implement cost-efficient and eco-friendly water strategies. It also provides advanced water treatment technologies, helping businesses comply with UK environmental regulations and reduce operational waste.
Veolia’s clients benefit from customized solutions, such as onsite wastewater recycling and efficiency monitoring, making it a leader for sustainability-driven enterprises in London.
Primary Expertise
Specializes in treating industrial water, reusing wastewater, and delivering environmentally conscious solutions for businesses.
Best Fit
Manufacturing facilities, industrial sites, and large commercial organizations.
Pricing: Tailored for each industrial or business requirement.
- Website: www.veolia.co.uk
- Phone: 0203 567 5300
- Address: Veolia House, 210 Pentonville Road, London N1 9JY
- Email: water.services@veolia.co.uk
Review: ★★★★★ “Our factory achieved major cost savings and greener operations with Veolia’s water solutions.”
7. Clear Business Water – “Simple and Affordable Business Water”
Clear Business Water focuses on small and medium enterprises (SMEs) in London, offering straightforward and budget-friendly water services. The company simplifies meter reading, billing, and account management, making it a hassle-free option for busy business owners.
One of its strengths is transparent pricing and no hidden fees, which appeals to businesses looking to control utility expenses. Their dedicated business support team ensures that queries and issues are resolved quickly.
For companies switching from regional water suppliers, Clear Business Water often provides competitive deals and cost-saving plans to lower monthly expenses.
Key Focus
Cost-effective and simplified water supply management for SMEs.
Most Appropriate For
Small and medium-sized London businesses prioritizing affordability and ease of management.
Pricing: Competitive business tariffs based on meter usage.
- Website: www.clearbusiness.co.uk
- Phone: 0333 014 3131
- Address: Etive House, 2 Flitch Way, Burnley, BB11 5PE
- Email: support@clearbusiness.co.uk
Review: ★★★★☆ “After moving to Clear Business, our water costs dropped, and managing payments became effortless.”
8. Wave Water Solutions – “Efficiency-Focused Commercial Provider”
Wave Water Solutions, a specialized business water provider, was established through a collaboration of Anglian Water and Northumbrian Water. The company serves medium to large businesses across London, providing tailored water management plans and environmental consulting.
Wave specializes in reducing water waste, leak detection, and monitoring usage, helping businesses achieve compliance and lower environmental impact. Its analytics-driven approach ensures companies can track consumption and optimize costs effectively.
With a commitment to corporate sustainability, Wave is a trusted partner for businesses pursuing net-zero goals or green certifications in London.
Special Strength
Business water efficiency programs and usage analytics.
Best Suited For
Enterprises, hotels, and commercial buildings seeking sustainable and cost-efficient water solutions.
Pricing: Variable business packages based on size and usage.
- Website: www.wave-utilities.co.uk
- Phone: 0333 207 9283
- Address: Northumbria House, Abbey Road, Durham, DH1 5FJ
- Email: info@wave-utilities.co.uk
Review: ★★★★★ “Wave helped us track water use, cut bills, and improve our environmental rating.”
9. Business Stream – “Smart Water Management for Enterprises”
Business Stream is one of London’s top business water retailers, well-known for its smart metering, leakage detection, and consumption management services. It serves a wide range of corporate and public sector clients, helping them optimize costs and meet sustainability goals.
The company offers custom reporting tools that allow organizations to analyze water consumption patterns, prevent unexpected leaks, and ensure regulatory compliance. Business Stream is also a trusted partner for multi-site companies, providing consolidated billing and usage insights.
Its approach to innovation and client education makes it a preferred water partner for businesses that demand more than just water supply.
Special Function
Comprehensive water management with a focus on analytics and efficiency.
Ideal Users
Large organizations, public institutions, and multi-site businesses seeking oversight and savings.
Pricing: Customized for medium to large enterprises.
- Website: www.business-stream.co.uk
- Phone: 0330 123 2000
- Address: 7 Lochside View, Edinburgh, EH12 9DH
- Email: customer.service@business-stream.co.uk
Review: ★★★★☆ “Great for monitoring water usage across multiple locations and reducing wastage.”
10. Everflow Water – “Digital-First Business Water Supplier”
Everflow Water is an emerging digital-first water retailer offering competitive pricing and intuitive online tools for business customers in London. Its user-friendly portal allows companies to track usage, download bills, and manage accounts entirely online.
The company appeals to tech-savvy SMEs and startups looking for modern utility management. Its competitive rates and transparent billing make it one of the fastest-growing water retailers in the UK.
Everflow also emphasizes environmentally conscious practices, encouraging businesses to adopt water-saving solutions. For those looking for flexibility and affordability, it provides an attractive alternative to traditional water suppliers.
Core Strength
Affordable business water plans with digital account management.
Perfect For
SMEs, startups, and digitally oriented companies seeking simplicity and savings.
Pricing: Budget-friendly business tariffs; varies by meter size and usage.
Contact:
- Website: www.everflowwater.com
- Phone: 0330 660 0400
- Address: Unit 5, Limeoak Way, Durham, DH1 5GB
- Email: info@everflowwater.com
Review: ★★★★☆ “Efficient, affordable, and easy to manage completely online.”
What Is the Quality of Drinking Water in London?
London’s water is safe, regularly tested, and compliant with UK and EU drinking water standards. The water in this region is generally hard, carrying higher levels of minerals such as calcium and magnesium. It is safe to drink, but it may cause limescale buildup in appliances and increase maintenance needs.
London Water Quality Comparison
| Company | Water Hardness | Coverage Area | Testing Frequency |
| Thames Water | Hard | Central & West London | Daily |
| Affinity Water | Hard | North & West London | Weekly |
| SES Water | Medium to Hard | South London | Weekly |
| Essex & Suffolk Water | Medium | East London | Weekly |
| Veolia Water UK | N/A (Commercial) | Industrial Services | Custom |
How Can Businesses Benefit from London Water Companies?
While households have little choice in their water supply, businesses can unlock significant advantages by carefully selecting a water retailer.
Cost Efficiency
Switching to a competitive business water supplier can result in lower tariffs and optimized billing. Many providers offer combined water and wastewater packages for greater savings.
Sustainability and Compliance
Retailers like Veolia and Wave Water help companies adopt eco-friendly practices through water recycling and efficient wastewater disposal.
Data and Water Management
Modern retailers provide real-time usage data, enabling businesses to detect leaks, reduce consumption, and plan for long-term savings.
Can You Switch Water Suppliers in London?
Switching depends on whether you are a household or a business customer.
- Residential Customers: Cannot switch, as your supplier is based on your address.
- Business Customers: Can switch freely to find the best rates and services.
Switching Overview
| Customer Type | Switching Allowed? | Notes |
| Residential | No | Supplier depends on your postcode |
| Business | Yes | Competitive water market for businesses |
What Should You Consider Before Choosing a Business Water Supplier in London?
For businesses in London, choosing the right water supplier can have a significant financial and operational impact. Since the water market deregulation in 2017, businesses can switch water retailers for better prices, services, and sustainability solutions.
Here are some key considerations:
1. Pricing and Tariff Options
Different suppliers offer variable business tariffs based on meter size, usage volume, and contract terms. Comparing quotes can help reduce operational costs.
2. Service Coverage and Reliability
Check whether a provider has strong local infrastructure and support, especially if you operate multi-site or high-demand facilities.
3. Sustainability and Efficiency Services
Numerous commercial water suppliers offer services such as identifying leaks, conducting usage efficiency checks, and implementing water reuse strategies. Choosing a supplier with eco-friendly services can help meet green business targets.
4. Customer Service and Account Management
A responsive support team and digital account tools make managing water bills and usage more efficient.
Conclusion
Selecting the right water company in London depends on your location, usage needs, and sustainability goals.
- Households can rely on major providers like Thames Water, Affinity Water, and SES Water for consistent supply.
- Businesses can benefit from Clear Business, Wave, and Everflow, which offer cost savings and efficiency solutions.
By understanding each company’s specialty and coverage, residents and businesses can make informed choices and contribute to sustainable water management in the city.
FAQs About Water Companies in London
Which is the largest water company in London?
Thames Water is the largest supplier, covering most of the city.
Can London residents switch water suppliers?
No, only businesses can switch suppliers.
How is water quality monitored in London?
Suppliers conduct regular tests to ensure water meets UK standards.
Which companies offer commercial water services?
Veolia, Wave Water, and Everflow Water focus heavily on business services.
How can businesses reduce water bills?
By switching to competitive suppliers and monitoring water usage.
What should I do during a water outage?
Contact your supplier’s emergency helpline listed on their website.
Is London water safe to drink?
Yes, it is fully compliant with safety regulations, though it is hard water.