According to the Beeb, A crackdown on tax avoidance and evasion by people who HM Revenue & Customs call "mass affluent" netted 60% more money in 2014.
Tax crackdown by HMRC - BBC News
So HMRC has a dept called the Affluent Unit. I wonder if they have a broke dept
Interestingly I see HMRC used Pinsent Masons to compile the report, who if you have ever had a run in with Getty Images, may know the name as they handle Getty UK copyright infringements.
Not to be trifled with! I wonder if they will take up the role as debt collectors?