The Telegraph obtained data from HMRC showing that it had increased the amount it collected as a result of self-assessment investigations from £609 million to £845 million last year.
It was already known that the taxman was focusing on a number of obvious sectors such as landlords and consultants, but small business owners also appear to be in its sights.
Tax investigations are not only stressful but eat up huge amounts of time, so being able to fend one off by having your records in good shape is very worthwhile.