Blog: Affinity Water’s WaterSave Tariff trial – a new way of charging

Affinity Water was the first water company to take the plunge with trialing a new way of charging customers based on how much water they use. Here the company’s project manager Lucy Hurst explains how the tariff trial is helping people to reduce their bills and value water – offering the rest of the industry a potential blueprint for fairer, more sustainable charging models.

In October 2023, Affinity Water became the first water company in England and Wales to trial a new-approach tariff for how customers are charged based on how much water they use. With our rising block tariff, we’re testing a bold new approach to see if smarter pricing can deliver greater fairness and encourage water efficiency. A rising block tariff charges more per volumetric unit of water for each subsequent block of water used. Our tariff design includes a free initial block, to assist affordability.

We are measuring the effects of the new tariff by comparison of a trial and control group. The trial group includes around 1,500 customers with AMR meters in Stevenage, Hertfordshire. These are meters which transmit information on water consumption that a water company can collect remotely.

These customers are receiving additional communications from us throughout the trial – for example, updates on how much water they are using – and so our trial is testing both the price change and an enhanced communication package.

Our data analysis has shown promising results, both from an affordability and demand perspective. Before the trial started, we expected at least 2 out of 3 customers to be better off on the new tariff if usage remained unchanged. Meter reads in the first year of the trial show we can now expect 3 out of 4 customers to see some reduction to their clean water bill.

When we compare ‘cash due at billing’ customers, we also see that the total amount of arrears is falling in the trial group and rising in the control group. Equally, the rate at which arrears are being cleared is faster in the trial than the control, indicating that the new tariff is putting people in a better position to pay. Therefore, we are seeing evidence of affordability improvement.

We’ve also seen an encouraging demand response from our provisional first year results. Both methods of measuring demand effect – using actual meter readings and using our in-house modelled demand tool – suggest that this new approach is actively helping customers make more sustainable choices.

At the mid-point of the trial in October 2024, we commenced a customer research project with Blue Marble Research to help us understand customer attitudes and lived experience of the new tariff. The findings showed us that rising block tariff was generally accepted by those participants in the trial, however all participants had concerns that larger households and vulnerable customers could be worse off.

This is about more than billing, it’s about creating a pricing system that supports those who need it most, whilst encouraging long-term water resilience. With initial results pointing to improved affordability and changes in usage behaviour, this trial could offer a blueprint for fairer, more sustainable charging models across the UK water industry.

We will continue to work with our customers, regulators and stakeholders to consult on our plans for the next phase of the trial, following the end of the trial in September 2025. We will also continue to share our learnings and findings with the industry.

We are delighted that our WaterSave Tariff trial has been shortlisted for the Groundbreaker Award at the Water Industry Awards on 24th June 2025. This recognises our commitment to creating smarter, fairer and more sustainable ways to charge for water.

For more information on the WaterSave Tariff, please visit Affinity Water’s website affinitywater.co.uk/billing/watersavetariff