They charge and extra 5 pounds to take off an existing shellac manicure if you buy through Treatwell. The manicure itself was good, but has started chipping off after a week.
Great value wax, clean salon, friendly staff. I do always find it a bit weird though how they wait in the room and watch you get undressed - I think every other salon I've been to let's you get settled and sorted on your own, but then again there's perhaps little point in affording one that modesty when they see everything anyway!