I started working at a bank one time as their BSA Officer and had this exact scenario. They said his construction firm paid employees and vendors in cash. Normal activity, no SAR ever filed. I added up cash activity over a year and it was around $1.2 million dollars with only one CTR filed because of a Friday being Mondays business day. I presented my team with similar construction companies that had absolutely no activity like this one outlier. I did a 314b with another bank I saw they had activity with and their answer confirmed what I already knew. He was doing the same thing in reverse over there. Making cash deposits from our withdrawals. It wasn't my job to determine if it is illegal or not, but with that much cash and no CTRs, what are the chances it is not structuring or intentional? Pretty slim.
But in some cases we have a business customer who deposits $8,000- $10,000 cash repeatedly, seldom or never exceeding $10,000. In order to file a structuring report on that, we have to assume that the customer is holding back funds. It could be that there was no intent to structure whatsoever, and it just happens that they tend to make about $8,000 or so in a day.