Overdressed or casual?

Since being in Brisbane, I've learned that ppl often underdress in corporate, but I was wondering with vacationer internships and things like that, is being overdressed considered punching a bit high/pompous? like blazer, and the full 9 yards, I figured it's always better to dress well well, but over here, I don't know what to do, for things like interviews and open houses in accounting

What's yalls experience?