Generally here in Bristol all Bristol City Council car parks are free for BB users (for now) but with council looking for money don’t know how much longer that will last.
NHS hospitals are free if you can find a space and of course double yellow lines are free however I’ve noticed more and more down town places where there’s double yellows now have the double yellow kerb bars on the pavement and is one of the reason why I don’t bother with down town money spending there any more unless I have no choice.