Readers’ forum: Should income from different trades be declared separately?

I’ve recently taken on a new sole trader client. He has fingers in a lot of pies. For instance he runs a small shop he does some landscape gardening he writes articles for the trade press he does occasional paid gigs as a drummer and he has a small piece of farmland on which he keeps a few pigs. 

His previous accountant lumped all of these activities together in a single profit and loss account and has described the business as ‘general trader’. HMRC has never raised any queries on the accounts.

All of these are unrelated activities and if looked at separately some would make a profit and some would make a loss. But by treating everything as a single source the previous accountant has effectively set off losses against profits without making any formal claims. What is my position? Can...