It’s still legal tender so they have to accept it. They don’t like it, but they do. Last time I visited Norway I held up the line at the grocery store trying to buy candy with cash that had been gifted to me. I’m not sure the cashier knew what to do with it.
Edit: many people telling me they are not required. From what I could find, cash is still “tvunget betalingsmiddel”, but there are some broad exceptions. Ref. So, I don’t think I was out of line expecting to pay cash at the grocery store. However, that was the only time I paid cash when I visited last time, so yeah, it’s basically cashless already.
Yep, I’m a big fan. It’s definitely an acquired taste, though.