Service incentive mechanism

Customer service

Ofwat’s service incentive mechanism (SIM) encourages water companies in England and Wales to provide better service to their customers. The SIM has resulted in customer satisfaction improving.

The SIM allows comparison of companies’ performance. It measures the following aspects of service delivery:

  • Where customers have made contact when something has gone wrong or appears to have gone wrong, for example, phoning about a billing error or writing to complain about a water supply problem.
  • A customer survey measuring how well companies have handled all types of customer contacts, not just when things have gone wrong.

Companies will receive rewards and penalties for their customer service performance during our price review.

Overall service incentive mechanism scores 2017-18

The average SIM score rose to 84.5 out of 100 in 2017-18 from 83.7 in 2016-17.

Anglian Water topped the table this year, with last year’s top performer – Portsmouth Water – in second place. Thames Water is bottom of the table again this year, although it has improved by over one point since last year. The four companies in the bottom four this year are the same as last year (albeit in a different order).

We are pleased to see further improvement in companies’ SIM scores as this suggests that the industry as a whole is improving its customer service, although we are disappointed to see no improvement in the number of unwanted contacts. We want to see companies doing better as we know that customers’ expectations are rising, and they expect the same levels of customer service they receive elsewhere.

Company SIM score
Anglian Water 88.3
Portsmouth Water 87.8
Bournemouth Water 87.5
South Staffs Water 86.9
Wessex Water 86.9
United Utilities 86.9
Dee Valley Water 86.5
Northumbrian Water 86.4
South East Water 85.5
South West Water 84.7
Dŵr Cymru 84.6
Yorkshire Water 84.2
Bristol Water 83.3
Severn Trent Water 83.2
Affinity Water 80.9
Southern Water 79.3
SES Water 78.7
Thames Water 78.4
Average 84.5

Customer satisfaction 2017-18 results

The annual SIM survey report shows the results of four customer satisfaction surveys conducted during 2017-18. The survey asks customers how satisfied they are with their water company’s handling of queries and resolving issues. We use an independent market research company to conduct the surveys.

The results show a positive trend, with average customer satisfaction rising to 4.40 out of 5, up from 4.37 last year.

Overall, customers of Anglian Water said they were most satisfied, with Wessex Water’s customers a very close second. Sutton & East Surrey’s customers were least satisfied.

Green for water and wastewater companies, blue for water-only companies

The SIM survey results have improved from 2016-17 and this is largely driven by the increase in the mean satisfaction score for wastewater services. However, satisfaction with billing services remains significantly higher than water and wastewater services. In 2016-17, the SIM scores were very similar for water-only companies and water and wastewater companies, but in 2017-18 the average SIM score for the water and wastewater companies was higher than the water-only companies.

Customers who contacted their water company online are significantly more likely to be satisfied with the handling of the matter than those who contacted their water company by phone.

Four out of five customers considered the matter for which they contacted their water company to be resolved. This figure is significantly higher for billing queries than water or wastewater. Those who considered the matter to be resolved were significantly more likely to be satisfied than those who considered the matter to be unresolved.

Download Ofwat SIM survey 2017-18 annual report

Numbers of complaints 2017-18

Companies report the number of complaints they receive to the Consumer Council for Water.

Download Household Complaints to water companies in England and Wales April 2017 to March 2018.

Although the three-year trend (2015-16 to 2017-18) for written complaints for household customers shows a strong improvement, the industry’s performance on unwanted contacts was disappointing. There has been no progress over the last three years, with the number of unwanted calls higher than it was in 2015-16.

We are proposing that the Customer Measure of Experience (C-MeX) will replace the SIM as the incentive for companies to improve the experience of residential customers from 1 April 2020 onwards. Further information on our C-MeX proposals can be found in section 4.4.1 on pages 64-67 of Delivering Water 2020: Our final methodology for the 2019 price review.