The message
from Another Dave contains these words:

Unless you have a meter the charges are based on the Council Tax band of
your house.

Strictly speaking (except for new builds) the charge is based on the
rateable value of your house at the time CT was introduced. AFAIK with
new builds they have some kind of fudge to produce a 'rateable value'.

However there seems to be plans afoot to do a CT revaluation to extract
even more tax from householders under the guise of being fair and no
doubt the rateable value link will soon disappear.

--
Roger