Top 5 Cheapest Water Suppliers for UK Businesses in 2025

UK businesses felt a jolt on 1 April 2025 when wholesalers lifted commercial water rates by as much as 35 per cent in some regions. The hike arrived on top of higher energy and payroll costs, so every saving now counts. Luckily, the competitive market that England opened in 2017 and Scotland in 2008 lets companies pick the cheapest water supplier UK-wide instead of paying the default tariff. This guide compares the five most affordable business water suppliers in 2025 and shows how to switch without fuss. 

How We Chose the Cheapest

We reviewed Ofwat’s 2025/26 wholesale price files and supplier price lists, then ranked providers on:

• Average combined water + wastewater £/m³ in their core regions
• Annual fixed charges for a single 20 mm SPID (the size most SMEs use)
• Savings for typical use—1,500 m³ a year, the median for light industry
• Extra perks such as smart meters or green tariffs

By focusing on cash costs rather than headline discounts, we highlight real savings you can bank. 

2025 Price Pressures at a Glance

Wholesalers say they need larger budgets for new reservoirs, pipe repairs and stricter environmental rules. Their solution: raise bills. Ofwat’s PR24 framework allows an average 20 per cent jump this year, with some southern regions topping 30 per cent. Businesses that stay on default contracts feel the full force, while those who lock rates now can soften the blow. 

The Five Best‑Value Suppliers

Wave Utilities

Wave, jointly owned by Anglian and Northumbrian Water, posts the lowest published combined charge in the country: £1.63/m³ for water and £1.88/m³ for wastewater in the North East. A business that uses 1,500 m³ pays about £5,300 a year, including a £42 water standing charge and £159 wastewater charge. Wave also offers free leak checks and automatic meter reads, which reduce surprise bills. 

Business Stream

Scotland’s pioneer retail arm keeps prices sharp south of the border too. In Yorkshire, Business Stream lists water at £2.18/m³ and waste at £2.72/m³. Despite the higher waste rate, clear online bills and a free water‑efficiency survey keep many manufacturers keen. A 1,500 m³ site pays roughly £6,140 a year—still below the Yorkshire default. 

Water Plus

The Severn Trent and United Utilities joint venture covers much of the Midlands and North West. Its £2.73/m³ water rate looks high, but the £1.57/m³ wastewater rate balances the equation, giving an annual bill near £6,310 for typical use. Water Plus pushes digital self‑serve tools and same‑day query replies—helpful if you juggle many sites. 

Castle Water

Castle wins fans with low standing charges and clear multi‑site invoicing. Thames‑region customers see £2.59/m³ for water and £1.71/m³ for waste, plus small fixed fees. A standard SME spends about £6,060 a year. Castle also installs data‑loggers that flag leaks in real time, slashing waste and costs. 

Everflow Water

Everflow rarely publishes rates but consistently quotes below default tariffs and bundles free smart meters. Trustpilot scores at 4.6/5 suggest the service matches the price. For many shops and cafes, Everflow turns out cheapest once quotes arrive, so it earns the final spot on our list. 

Quick Comparison Table

Beyond Price: Picking the Right Partner

Price leads most decisions, yet service often drives long‑term savings. Check:

• Online portals that show daily reads
• UK call centres with fast response times
• Green options—many business water suppliers let you match usage with water‑efficiency projects
• Multi‑utility bundles that place water, electricity and gas on one bill

Ask about meter upgrades, too. Smart AMR meters cut admin and flag leaks early, often paying for themselves within a year.

How to Switch in 2025

Follow these steps to protect your cash before the next wholesale rise hits:

• Gather bills and your SPID. The Supply Point ID sits on the first page.
• Check contract end dates. Most run 12 months; give 30 days’ notice.
• Request quotes three months out. Use Utility4Business to compare live offers.
• Pick a deal and sign digitally. Your new supplier handles the hand‑off.
• Read your meter on switch day. This secures an accurate final invoice.

Conclusion

Wholesale charges will keep rising as networks modernise, yet smart businesses won’t let costs drift. Wave, Business Stream, Water Plus, Castle Water and Everflow top the 2025 value charts, but the best deal for you depends on region, use and service needs. Review your bill, compare offers with Utility4Business and switch early. By acting now, you can beat the next price rise and lock in savings for the year ahead.