What are some tax filing "red flags" that can trigger an audit?

What are some tax filing "red flags" that can trigger an audit?

John Stoller, CPA (Certified Public Accountant) gives expert video advice on: How does the IRS decide who to audit?; How can I avoid an audit?; What is "tax fraud"? and more...

Another factor to be considered in the audit of returns is whether the expenses that you're claiming for a particular category are much higher than the average expenses claimed in that category by people in your position. Another item that they would look for in an audit would be unusual expenses that are way out of line. I once had a client who proved absolutely he had $120,000 in legitimate deductible automobile expense. However, in preparing the return, I refused to put down the $120,000, because that number itself was too large without something else to call part of it.