My family history is upper class, great grand parents on father's side owned a arge porcelline factory , WW2 put an end to that (factory bombed to nothing). My parent were middle class by education and pbringing, both with PhDs, my dad was a professor before retiring. I was raised middle class but my parents ended up n financial difficulties so economically I was working class.
I have a phd, travel the world for work, command a reasonable salary. I consider myself middle class.
Owning factory and industry doesn't make you upper-class sorry, upper class in Britain means landed gentry, aristocracy, and members of 'society'. Upper class means 'old money' as a category, and industrial wealth and money from industry is decidedly
not upper class, in fact it's new money, nouveau riche, arrivistes, etc. and it is actually looked down upon. Your great-grandparents became rich as part of the industrial bourgeoisie, who aspire towards upper-class property ownership but have to basically 'buy' all of their status with material wealth. Upper class people in the British system normally insist on heredity, tradition, long lineages, etc. and the family estate is normally always owned and inherited, not bought. Upper class people appear in society 'who's who' magazines, they have debutantes balls and all enjoy a good gossip and hunt with one another.
Ironically, in the British system the upper-classes are actually very often much less rich than the affluent middle-classes. Their 'wealth' is in social and cultural capital, rather than material wealth. The old dictum, "you can't buy class", etc.
Not meaning to rain on your parade or anything, but so many people say they are upper-class when they are not.
As for middle-class, I would say it depends on tastes and socio-cultural norms... for one thing university-education as a commonplace is a major factor in class stratification. Professional jobs don't necessarily mean middle-class so much as (private) education, mannerism, culture, taste, etc. A hard-working professional 'well-to-do' working class family would probably never go to the theatre, or enjoy polo, or hunt, or anything like that - even if they could afford it. Middle-classness in Britain is much more traditional and cultural, rather than money based (the middle-class as an economic group, mostly denoting 'comfortable', tends to be an American classification). A safe and sound guarantee of always making it to the upper echelons of the middle-classes are the traditional professions: academia, law, medicine, etc. But again, lacking a blood-line to be upper-class. They are merely at the top of the mobile middle-classes through their hard-work and ambition.
As most of my family are public school educated, I'd say we're upper-middle class. To be upper we'd need ties to the aristocracy or gentry which we sadly/gladly (take your pick) do not have. I'm completely indifferent, but I'm young and naive and like to believe in idealistic fallacies such as meritocracies.
I also don't understand why people feel the need to bash the working-class here, or make snide remarks. The only true comment that makes is one about your own insecurity.