I had a Danish friend at University and she asked me how good her English was. I told her it was perfect, but she would never be taken for someone British as there was no sense of "place" or "class" with her accent.

You can normally make assumptions about someone's place or class within a few words or phrases in the UK

EG "fillum" for "film" for people from the North East, "supper" instead of "dinner" for middle/upper class people.