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About Castle Water: business water retailer review

Castle Water Limited. Independent and privately owned, with no ties to any water wholesaler (WPGSS Limited is recorded as majority shareholder on the Companies House PSC register).

England & Scotland

At a glance

Castle Water is an independent business water retailer founded in 2014 and headquartered in Blairgowrie, Scotland, serving over 250,000 business customers across more than 450,000 supply points in England and Scotland.

Last reviewed 10 June 2026. Facts are drawn from Castle Water's own published pages, Companies House and the MOSL dashboard snapshot (March 2026). Verify anything you intend to rely on against the current source.

Castle Water: key facts

Parent and ownership
Independent and privately owned, with no ties to any water wholesaler (WPGSS Limited is recorded as majority shareholder on the Companies House PSC register)
Founded
2014 (Castle Water Limited incorporated at Companies House on 17 April 2014; the company's own about page also states it was formed in 2014)
Headquarters
Blairgowrie, Perthshire, Scotland (registered office: 1 Boat Brae, Rattray, Blairgowrie PH10 7BH)
Leadership
John Reynolds OBE, Chief Executive Officer
Supply points (MOSL snapshot, March 2026)
199,306 SPIDs
Companies House
SC475583
Regions served
Both England and Scotland. Its about page states that businesses, public bodies and charities in England or Scotland can choose their water and wastewater retailer. Heritage as the retailer for the former Portsmouth Water (2016) and Thames Water (April 2017) non-household customer books in England; Scottish base expanded by acquiring Brightwater (approximately 12,000 Scottish business customers) in February 2025, with the Brightwater Scottish licences subject to a WICS transfer notice published January 2026. The site references England and Scotland only, not Wales.

Services Castle Water publishes

Taken from the retailer's own published service pages.

  • Automatic meter reading (AMR), including limpet readers
  • Leak detection, leak repairs and leak reporting
  • Water efficiency audits and audit checklists
  • Trade effluent services, including applications for trade effluent consent
  • Multi-premises and large-business water management, including water management plans
  • Wastewater management
  • Water bill validation
  • New water connections
  • Emergency business water supply and contingency planning
  • Self-service customer portal for billing, meter readings and support cases

Castle Water deemed and out-of-contract rates

When a site takes supply without a negotiated contract, for example after moving in or letting an agreement lapse, the retailer bills on its published deemed or out-of-contract terms, which differ by wholesale region and are updated each charging year. We never republish the figures: they change annually, so the only reliable source is the current document.

Castle Water publishes its deemed and out-of-contract terms in its own charges documents, linked below. Check the document for your wholesaler region and charging year before comparing it against a negotiated offer.

Castle Water published charges

Who Castle Water are

Castle Water is an independent business water retailer headquartered in Blairgowrie, Perthshire. The licensed entity, Castle Water Limited (Companies House SC475583), was incorporated on 17 April 2014 and remains privately owned, co-founded by chief executive John Reynolds OBE and Graham Edwards, with WPGSS Limited recorded as majority shareholder on the Companies House PSC register and press reports describing backing from the Pears family. The company describes itself as the UK's largest independent business water retailer, with more than 250,000 customers, over 450,000 supply points across England and Scotland and a team of over 450 people.

The business grew by acquiring incumbent retail books as the markets opened to competition. It took on Portsmouth Water's non-household customers in 2016, was appointed in July 2016 to serve Thames Water's business customers (with the book transferring at the April 2017 opening of the English non-household market), and in February 2025 acquired Brightwater, a Scottish retailer supplying approximately 12,000 business customers. Castle Water applied to the Water Industry Commission for Scotland in September 2025 to transfer Brightwater's Scottish licences, and WICS published a notice proposing to grant the transfer in January 2026. For the year to March 2024 the company reported group revenue of £434.4m, gross profit of £47.5m and adjusted EBITDA of £15.0m.

Castle Water publishes a broad set of business water services, including automatic meter reading, leak detection and repair, water efficiency audits, trade effluent support, bill validation, new connections and multi-premises water management, and charges deemed and out-of-contract customers under per-wholesaler Scheme of Charges documents held in its customer portal. Its service record includes both recognition and criticism: MOSL named it the top-performing large retailer for Market Performance Standards in 2023/24, while CCW, the statutory consumer body, publicly pressed it over high complaint volumes in 2018 and highlighted further complaint increases in its 2020-21 report, before market-wide complaints fell to their lowest level since 2016/17 by 2022-23.

Strengths

  • Scale: describes itself as the UK's largest independent business water retailer, serving over 250,000 customers and more than 450,000 supply points across England and Scotland, with over 450 staff (about page and 2023-24 results announcement).
  • Independent of all water wholesalers: privately owned, founder-led since 2014, with John Reynolds OBE as CEO throughout (about page, Companies House, 2023-24 results).
  • Market performance recognised by the market operator: named top-performing large retailer for Market Performance Standards in MOSL's 2023/24 Annual Market Performance Report, and reported an MPS score of 98.26% with a 99.98% data quality score in 2025 (castlewater.co.uk news, MOSL report coverage).
  • Dual-market coverage with deep incumbent heritage: took on Portsmouth Water's non-household book in 2016 and Thames Water's business customers at the April 2017 market opening, and expanded in Scotland by acquiring Brightwater in February 2025 (castlewater.co.uk news pages, WICS notice).
  • Publishes full annual financial results, unusual transparency for an unlisted retailer: FY 2023-24 revenue £434.4m, adjusted EBITDA £15.0m, net debt reduced to £65.9m (results announcement).

Considerations

  • Historic complaints record: CCW, the statutory consumer body, publicly told Castle Water to address 'unacceptable' complaint numbers in 2018 (Castle Water accounted for around 44% of the 1,630 retailer complaints CCW received between September 2017 and February 2018), and CCW's 2020-21 report again flagged large complaint increases, with Castle Water and Water Plus together accounting for 7 in 10 written complaints; market-wide complaints had fallen to their lowest level since 2016/17 by CCW's 2022-23 report.
  • Current Scheme of Charges documents (including deemed and out-of-contract charges) sit behind the customer portal rather than on open web pages; the public scheme-of-charges page redirects users to portal.castlewater.co.uk.
  • No direct phone number or email address is published on the main contact page; customer contact is routed through web chat (Monday to Friday, 9am to 5pm) and the online portal.
  • Water-only retailer covering England and Scotland: businesses wanting a single supplier across water, gas and electricity, or with Welsh premises, would need additional arrangements (its site covers water and wastewater services in England and Scotland only).

Frequently asked

Castle Water: questions answered

Who owns Castle Water?

Castle Water is independent and privately owned, with no ties to any water wholesaler. The Companies House PSC register for Castle Water Limited lists WPGSS Limited, a London-registered holding company, as majority shareholder, alongside Shamil Anil Chandaria with 25 to 50 per cent of shares. The business was co-founded in 2014 by chief executive John Reynolds OBE and Graham Edwards, and press reports describe financial backing from the billionaire Pears family, the London property investors behind the William Pears Group.

What are Castle Water's deemed and out-of-contract water rates?

Castle Water charges deemed and out-of-contract customers under its published Scheme of Charges, with a separate document for each wholesaler region (for example the Thames Water and South East Water areas) based on that wholesaler's charges. The current Scheme of Charges documents are held in Castle Water's customer portal, reached via the scheme of charges page we link to from this page. Rates are updated each April, so always check the current year's document for your wholesaler region rather than relying on older figures.

Can Castle Water supply my region?

Castle Water supplies eligible businesses anywhere in England and Scotland, the two open non-household water markets. Its website states that businesses, public bodies and charities in England or Scotland can choose their water and wastewater retailer. It inherited large customer bases in the Portsmouth Water area (2016) and the Thames Water area (April 2017 market opening), and expanded in Scotland by acquiring Brightwater, with around 12,000 Scottish business customers, in February 2025. Its site does not reference supply in Wales.

How do I contact Castle Water?

Castle Water handles customer contact through web chat on its website, open Monday to Friday, 9am to 5pm, with a virtual agent outside those hours, plus a self-service portal at portal.castlewater.co.uk for billing, meter readings, moving premises and support cases. No direct phone number or email address is published on its main contact page. Its registered office is Castle Water Limited, 1 Boat Brae, Rattray, Blairgowrie PH10 7BH, and a separate emergency contacts page covers urgent supply issues.

Is Castle Water suited to multi-site businesses?

Yes, Castle Water publishes dedicated multi-premises and large-business water management services covering account management across multiple locations. Its published case studies include Suez, which switched more than 200 sites to Castle Water, and the company reports serving over 250,000 customers across more than 450,000 supply points in England and Scotland, which indicates substantial multi-site capability. Multi-premises management, water management plans and large-business services each have their own pages on castlewater.co.uk.

What happens if Castle Water exits the market?

Your water supply would continue uninterrupted and your account would transfer to another retailer. In England, Ofwat's Interim Supply Code allocates the customers of a failed or exiting retailer to alternative retailers, with no action needed from customers and no change to supply while the transfer happens. For context on financial resilience, Castle Water's 2023-24 results reported net debt reduced to £65.9m with closing cash of £34.5m, and Ofwat notes interim supply arrangements have operated in the small retailer failures seen since 2017.

When did Castle Water take over Thames Water's business customers?

Castle Water was appointed in July 2016 to provide retail services, including invoicing, billing and payment collection, to Thames Water's business customers, and the retail book transferred when the English non-household water market opened in April 2017. It had taken on Portsmouth Water's non-household retail customers in 2016. Many businesses in the Thames region remain on deemed contracts with Castle Water dating from that transfer, which is why it is the default retailer billing many London and South East businesses.

How big is Castle Water?

Castle Water describes itself as the UK's largest independent business water retailer, serving more than 250,000 customers and over 450,000 supply points across England and Scotland with a team of over 450 people. Its 2023-24 results reported group revenue of £434.4m, gross profit of £47.5m and adjusted EBITDA of £15.0m. MOSL named it the top-performing large retailer for Market Performance Standards in its 2023/24 annual report, and the company reported a 98.26 per cent MPS score in 2025.

How we work with Castle Water

We are an independent broker, not the retailer. When you tender through us, Castle Water is quoted against the whole licensed Open Water retailer panel, with the wholesale charge, retailer margin and our margin shown separately on every offer. No retailer pays for placement on this page and this profile is not a ranking. Our guide to how to compare business water suppliers covers the criteria we score offers on, and our step-by-step guide to switching business water supplier walks through the CMOS process, with no interruption to supply.

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