Trade? Give me a break.
Anyway I was called for 'interview' by HM Customs late last year and asked to explain why my declared earnings had gone up so much on the previous four years.
They didn't believe when I said what was earnable, but when I told them about the w/c forums on the www they had a look and on a second interrogation

they then said that they would be taking a much closer look at w/c income, especially what they earn/declare (two different things

). Well, that was September, and two weeks ago they opened a formal investigation into me and said that they anticpated doing more of these.
So watch your back with what you claim you earn and what you tell HM Customs.
Obviously I can't say any more at the moment but I don't think its going to be easy ride over the next few months.
Oh and the more you talk about wc being a 'trade', (titter!) the more it looks like you CAN earn big bucks, but you try hiding that from them.