When I work at home it is mostly pajamas.

But work at home isn’t business casual. Business casual is what to wear in a less formal public setting, like a conference or office. While some people have started to wear jeans in those settings, I have never seen anyone in flannel shirts and broken in hats in a setting described as ‘business casual’.

Yes, some offices don’t have dress codes and that is fine to wear, but agsin they don’t call themselves ‘business casual’ either.