Sir – May I use your columns to help those Oxford customers of Thames Water who, for technical reasons eg communal hot water in a block of flats, cannot have a meter, and are still paying through the nose on the old ‘rateable value’ basis?

They’re entitled instead to be billed an ‘assessed’ charge, a set figure reflecting typical water use for a dwelling like theirs.

For some, especially single occupants, this might prove much cheaper. Provided they know about it, as many don’t. I was one.

Yet Thames Water deliberately (it has told me) doesn’t tell such people about this alternative, until after they’ve asked for a meter and been told that’s impossible.

As they probably knew already and how many rational people ask for something they know they can’t have? “Let ‘em stay in the dark” is Thames’s view.

But doesn’t Ofwat, the water regulator, disapprove of this secrecy? Not at all: it actively approves. It is so (rightly) keen on meters that it (absurdly) is against “promotion” for any non-metered charge —even to inform households that cannot be metered, about a version that might slash their bills! They can be ripped off blind, for all Ofwat cares. So much for Ofwat’s empty boast of “protecting consumers”.

Stephen Hugh-Jones, London NW8