@EdithWeston
We may have a very different idea of relaxed business casual. I've been working in offices for the last 20 years and haven't worn a tie or worked with any men apart from one older gentleman who wore a tie.
Generally dress code was shoes, smart trousers and a collared shirt.
I've noticed a distinct shift towards even more casual with my last contract having people wearing sandals, shorts and t-shirts to the office including reasonably senior management (yes it was IT)
However, if working in a conservative financial or legal office then I agree for men a jacket and tie would be normal.
I can't say I've ever seen women wearing a tie though, I associate that more with early 2000s skate punk, Avril Lavigne style.