What kind of family has a combined income of £22k? Are you including kids under 16 in that family? Only one person is responsible for the council tax (in effect) so if the others want to chip in then that's up to them. I can confirm that my 26 y.o son chips in the square root of fuck all! I will concede it can be indirectly regressive. Be nice if they had the same egalitarian approach with Income Tax, I bet I'd be quids in.