How the open water market actually works
Since April 2017, every business, charity and public-sector site in England has been free to choose its water retailer. The wholesaler, your regional network operator like Thames, Severn Trent or United Utilities, still owns the pipes and processes the water. What changes when you switch is the retailer: who bills you, who handles meter reads, who resolves queries and who finds savings on your tariff.
Wholesale charges are set regionally by Ofwat and are the same regardless of which retailer you choose. The retailer adds a margin and a service component on top, so switching is about lower margin, better service, accurate meter reads and historic-credit recovery, not about cheaper water itself.
Supply, waste-water and trade effluent
Most business water bills carry three separate lines: clean-water supply (volumetric + standing), waste-water/sewerage (volumetric + standing, sometimes including surface-water drainage) and, for industrial users, trade effluent charges based on a Mogden formula reflecting volume and effluent strength.
We audit each line independently. Surface-water drainage rebates, voids on unoccupied premises and meter under-reads on small/medium meters are the three most common sources of recoverable credit we find on first review.
Historic audits and leak monitoring
A historic bill audit is normally free and works on a contingent basis, you only pay when refunds land. Common findings include incorrect meter sizing, RV-based estimates that should have moved to metered billing, and surface-water drainage charges for sites where surface water doesn't actually enter the public sewer.
Once switched, half-hourly meter monitoring with overnight-flow alerts catches leaks early. A single overnight leak on a 25mm meter can cost a four-figure sum a month if it runs unnoticed.