Periodically, every 6 months or so, do a couple of things that will detect or prevent theft and fraud in your business.
From you accounting and Payroll software run a report of employee addresses and Vendor addresses. Compare them. Do any of them look the same or are street numbers close by? Go into it deeper, if they are.
Look for checks written in round numbers – particularly large amounts relative to your average check amounts. You should not have many but look at the ones you have. Are they genuine? Look at recurring payments, especially if they are small. Where are they going and are extra amounts being paid relative to a twelve month period.?
Review credit card payments and whether it is in the name of the company or individuals.