Affinity and Wessex lead in the first batch of results that will inform BR-MeX scores

(by Karma Loveday)

MOSL has published the first round of wholesaler business retail service performance results that will be factored in to determine the first BR-MeX payments for water companies.

BR-MeX, the business customer and retailer measure of experience, was introduced at PR24. Wholesalers will be rewarded or penalised based on how retailers (R-MeX) and business customers (B-MeX) score their service performance, with a 50:50 weighting.

Table 1

Table 1 shows wholesalers’ R-MeX results in the first of two surveys that Ofwat will use to determine the retailer element of BR-MeX. It was conducted in August 2025, based on responses from 17 retailers supplying 99% of supply points in the market. A second survey will follow in February 2026. For the first half, Affinity Water has held on to its long established leading position, with an overall score of 8.83 compared to an industry average of 8. Yorkshire Water is in bottom place with 7.15. Thames Water made the biggest improvement on its February 2025 score, moving up from 14th place to 10th.

Table 2

Table 2 shows the first quarter results of the new B-MeX survey. Here, Wessex Water leads with 82.75, closely followed by Northumbrian Water, compared to an industry average score of 70.75. South West Water is in last place, with 60.67. Results from three more quarters will follow.