I eventually got a response from the DCMS around the start of this month. It was the usual bland, incoherent stuff saying carol singing did not inherently need a licence(whether religous or secular) but if, for instance, a business arranged for them to sing outside his shop then a licence would be required.

First of all you were lucky they replied so quickly.

Secondly, what they usually do in my experience is say it is a matter for local councils. The councils refer you back to the DCMS!!

I was aware of the carol singers near Norwich but it was a bit too close to Xmas to add my two pennorth at the time. There is no doubt in my mind that there will be continual absurdities, and we need to keep highlighting them.