Class is a social relationship rooted in production.

Either you own resources critical for the production process, or you sell your labour power to those who do.

If the latter, you’re either a professional with some autonomy and some assets, or a worker with little of both.

Class has nothing to do with:
-your accent
-where you live
-where you grew up
-what your parents do
-where you went to school

These things remain important in supporting certain individuals to change their class position, but they don’t come into the definition of class.

Before I get accused of economism I’d like to point out that there’s no such thing as ‘the economy’, only social relations of various kinds.

What we’re establishing isn’t ‘what matters more - the social or the economic?’ Its what kinds of social relation shape class position.