If you're a social landlord – such as a local council or housing association - that has a billing and service arrangement with a water company, then you need to pay close attention to a recent judgment from the High Court.

It ruled that Southwark Council in London had for many years been overcharging its 37,000 tenants for water and sewerage services. The council will have to pay back the money, and - at an average of £240 per property. The total liability could exceed £8m.