The taxman won't want your tin of bickkies or your box of chocolates but he will tax you on them? he will also charge you an average of what he thinks you may get, based on the amount of customers you have, its then up to you to prove you didn't get that much?
Believe me I know

He also stung one of my mates in smithfield market in Birmingham and he just pushes a barrow around he used to get a couple of quid a day, the taxman charged him an avarage and it was way more than he got in tips.
The taxman would have a field day with half of you guy's,once he gets his teeth into you, he won't let go.