Castle Water continues to lead the UK business water retail market, achieving the highest Market Performance Standard (MPS) score across the top 10 retailers in October 2025 — reaching a market-leading 98.26%.
But that’s not all. We’re proud to consistently maintain exceptional performance in three key customer service and data areas:
| Rank | Retailer | MPS Score (%) | Missed/Late Tasks (%) | Data Quality (%) | Complaints to Retailer | Complaints to CCW |
| 1 | Castle Water | 98.26 | 1.74 | 99.98 | 0 | 0 |
| 2 | Water 2 Business | 98.09 | 1.91 | 99.96 | 0 | 0 |
| 3 | Wave | 97.82 | 2.18 | 99.88 | 0 | 0 |
| 4 | Business Stream | 96.82 | 3.18 | 99.98 | 0 | 0 |
| 5 | Pozitive Water | 96.16 | 3.84 | 100 | 0 | 0 |
| 6 | Clear Business Water | 96.07 | 3.93 | 99.77 | 0 | 0 |
| 7 | Water Plus | 95.1 | 4.9 | 100 | 0 | 0 |
| 8 | Everflow | 94.57 | 5.43 | 99.88 | 0 | 0 |
| 9 | Pennon Water Services | 94.51 | 5.49 | 99.94 | 0 | 0 |
| 10 | SES Business Water | 93.48 | 6.52 | 99.98 | 0 | 0 |
Data reflects October 2025 MOSL performance tables for retailers
What Does This Mean for You as a Castle Water Customer?
- Reliable Billing & Service: Our MPS score reflects how reliably we deliver core market processes like meter reads and customer updates. A 98.26% score is well above industry average — and proof that we get things right first time.
- Exceptional Data Accuracy: Our Data Quality Score of 99.92% means fewer billing issues, faster service resolution, and smarter water usage tracking.
- Fewer Complaints: Low levels of customer complaints – both to Castle Water and to the Consumer Council for Water (CCW) – show that we listen, respond, and resolve issues quickly and fairly.
Why Our MPS Leadership Matters
Castle Water’s outstanding performance isn’t a one-off. We’ve consistently led the market for:
- Market compliance
- Customer satisfaction
- Data integrity
- Transparency and fairness
This reflects our investment in:
- Leading digital systems and automation
- Staff training and expert customer care
- Accurate billing and proactive issue resolution
What Are Missed or Late Tasks?
These represent any failures to complete required market transactions (like meter reads or updates) on time. A lower percentage means a retailer is more efficient and dependable.
About Castle Water
We’re the UK’s largest independent business water retailer, supplying over 500,000 supply points. Since market deregulation, we’ve focused on giving customers what they really want: fair prices, accurate billing, and excellent service.
Whether you’re a small business or a multi-site organisation, you can trust Castle Water to deliver industry-best service — and we have the numbers to prove it.
Switch to Castle Water – The UK’s #1 for Business Water Performance
Why Choose Castle Water?
- Highest Market Performance Score – 98.26%
- Leading Data Accuracy – 99.92%
- Top Truspilot scores – more 5* reviews than all other water retailer combined
- Trusted by more than 450,000 UK supply points
- Simple, accurate billing with expert support
Switching is easy – no disruption to supply. Just better service, better data, and a team that puts your business first. Get a Quote Now


