How does the business water market work?
The business water market in England operates differently to the domestic market, where households are tied to their regional supplier. Since April 2017, most businesses, charities, and public sector organisations in England have been able to choose their water retailer from a range of licensed providers.
Your water retailer handles your billing, customer service, and account management. The physical supply - the pipes and infrastructure - remains the responsibility of the wholesaler for your region and does not change when you switch. In Scotland, the business water market has been open to competition since 2008. In Wales, the market has not yet been deregulated, so businesses there remain with their regional supplier.
Who are the key players in the business water market?
Understanding who does what in the business water market makes the switching process easier to navigate.
Retail suppliers
These are the companies that compete for your custom. They buy water and wastewater services from wholesalers and provide billing, account management, and customer service directly to businesses.
Wholesalers
Wholesalers own and operate the network of water pipes, mains, and treatment works. They sell water and wastewater services to retail suppliers. Your wholesaler does not change when you switch retailer.
Ofwat
Ofwat is the economic regulator for the water sector in England and Wales. It is also the market's licensing authority - suppliers must hold an Ofwat licence before they can offer water services to business customers.
Open water
Open Water is the government programme that opened up the business retail water market. Led by Ofwat, Defra, and MOSL, it shares information about the market with business customers and maintains an online catalogue of licensed retailers.
MOSL
MOSL is the market operator responsible for ensuring the market functions simply and efficiently. It facilitates the transfer of customer information when a business switches retail supplier.
WICS
The Water Industry Commission for Scotland is responsible for regulating the water market in Scotland.
Can my business switch water supplier?
England
Most businesses in England with a meter can switch their water retailer. This includes small businesses, larger commercial operations, charities, and public sector organisations. If your premises are connected to the mains supply and you receive a metered bill, you are almost certainly eligible to switch.
Scotland
Business customers in Scotland have been able to choose their water provider since 2008. Business Stream is the dominant retailer, but licensed competitors also operate in the market.
Wales
The non-domestic water market in Wales has not been deregulated. Businesses in Wales are served by Dŵr Cymru (Welsh Water) and cannot currently switch to an alternative retailer.
Why review your business water supply?
Potential cost savings
Water costs are often treated as a fixed overhead and left unreviewed. In practice, different retailers charge different rates for the same wholesale supply, and some offer tariff structures better suited to specific usage patterns. Comparing your options is the most reliable way to find out whether you are on a competitive deal.
Better billing and account management
Switching is not purely about unit costs. Some retailers offer better billing accuracy, clearer itemisation, online account management, and more responsive customer service. For businesses managing multiple sites or complex usage, these factors can be as valuable as a lower unit rate.
Consolidated contracts for multiple sites
If your business operates across several premises, some water retailers offer consolidated billing across all sites. This reduces administrative overhead and can simplify your budgeting.
Leak alerts and consumption monitoring
A number of business water retailers provide usage monitoring tools and proactive leak detection as part of their service. These features can help identify inefficiencies and avoid unexpectedly high bills caused by undetected leaks.
What affects your business water bill?
Business water bills are typically made up of several components:
Volumetric charge
The amount you pay based on actual consumption, measured in cubic metres. This is the core element of most bills and the figure most directly influenced by your usage habits.
Standing charge
A fixed daily or annual charge that covers the cost of maintaining your connection to the water network, regardless of how much you use.
Surface water drainage
A charge for managing rainwater runoff from your site. The amount is usually based on the size of your premises and can vary significantly between different property types.
Wastewater (Sewerage) charge
The cost of removing and treating wastewater from your premises. This is typically calculated as a proportion of your incoming water volume.
Understanding each element of your bill makes it easier to identify where savings might be possible and to compare like-for-like when reviewing alternative tariffs.
How to switch business water supplier
Switching is a straightforward process. Your new supplier manages most of it on your behalf.
Find the right supplier
Before comparing, note down what matters most to your business — whether that is price, customer service, online account management, or support with water efficiency. Use the Open Water online catalogue to identify licensed retailers operating in your area.
Get a quote
Have your Supply Point Identification (SPID) number to hand — this can be found on your most recent water bill. Your SPID is used to identify your premises and generate an accurate quote.
Sign up and switch
Once you have agreed a tariff, sign an agreement with your new supplier. They will contact your current supplier to notify them of the switch. You will need the following information:
Your organisation's name
Your business address, including postcode
Your annual water consumption
Contact name and phone number for the premises
Your annual spend, demand profile, and unique property reference number are helpful but not essential.
There is no interruption to your water supply at any point during the process. Most switches complete within a few weeks, depending on your current contract terms.
Tips for reducing your business water costs
Switching supplier is one way to reduce costs, but it works best alongside a broader approach to water efficiency.
Audit your usage
An annual review of your metered consumption can surface inefficiencies — particularly in businesses with high water use such as catering, manufacturing, or hospitality. Comparing usage year-on-year helps identify anomalies that may indicate leaks or equipment issues.
Fix leaks promptly
Even a small dripping tap or running toilet can waste thousands of litres of water a year and add meaningfully to your bill. Some water retailers offer free leak detection services as part of their business packages.
Install water-efficient equipment
Small upgrades can deliver significant savings:
Automatic or spray taps can reduce tap water usage by up to 70% compared to manual taps
Dual-flush toilets can cut toilet water use by up to 70%
Passive infrared sensors on urinals can reduce flushing water use by up to 75%
Dropping the water level in cisterns — for example by placing a displacement device inside — can save up to 5,000 litres per year
Consider a water audit
For higher-usage businesses, a professional water audit can identify specific savings opportunities and help you understand whether your current tariff structure is well matched to your usage profile.
Consider rainwater harvesting
Rainwater storage tanks allow you to capture and recycle rainwater for non-potable uses such as toilet flushing or external cleaning. Tanks are available in a range of sizes to suit different premises.
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Business water supply frequently asked questions
Does switching business water supplier affect my water supply?
No. When you switch water retailer, only the company managing your billing and account changes. The physical supply - the pipes, pressure, and infrastructure - is maintained by the regional wholesaler and is unaffected by the switch.
How do I find out who my current business water supplier is?
Your current water retailer will be named on your most recent bill. If you are unsure, you can also check with the Open Water portal (open-water.org.uk), which maintains a register of licensed retailers and can help you identify your current supplier.
What is a SPID number and where do I find it?
A Supply Point Identification (SPID) number is a unique reference that identifies your premises in the water market. You will need it when requesting a quote from a new supplier. It can be found on your most recent water bill.
Can I switch business water supplier mid-contract?
This depends on the terms of your current agreement. Some contracts allow switching at any time, while others include a minimum term or notice period. Check your contract before initiating a switch to understand whether exit charges apply.
Is there a difference between a water supplier and a water retailer?
Yes. The water wholesaler is the company responsible for the physical infrastructure — the pipes that supply water to your area. The water retailer is the company you have a contract with for billing and customer service. You can switch retailer without changing your wholesaler.
Do businesses in Scotland and Wales have the same switching options?
Scotland's business water market has been open to competition since 2008, so most Scottish businesses can compare and switch. Wales has not yet deregulated its non-domestic market, so businesses there cannot currently choose an alternative retailer.
What size of business can switch water supplier?
Most metered business customers in England are eligible to switch, regardless of size. This includes sole traders, SMEs, larger commercial businesses, charities, and public sector organisations. If your premises have a meter, you are almost certainly eligible.
How often should I review my business water tariff?
At minimum, you should review your water supply contract whenever it comes up for renewal. Given that water costs are often left unreviewed for years, an annual review is a good habit — even if you ultimately decide to stay with your current supplier. As with energy and broadband, setting a calendar reminder before your renewal window closes gives you time to compare and negotiate.