Key Takeaways The IRS identifies "badges of fraud" — specific indicators that suggest willful tax evasion rather than honest mistakes Revenue agents are trained to look for these red flags during every civil audit Multiple badges of fraud significantly increase the likelihood of a referral to IRS Investigation Many red flags can be explained through legitimate means — proper documentation is your best defense Having experienced tax counsel during an audit can prevent a civil matter from becoming complex What Are Badges of Fraud? Badges of fraud are indicators or characteristics that the IRS uses to evaluate whether a taxpayer's underreporting or noncompliance was the result of fraud rather than negligence or honest mistake. They are documented in the Internal Revenue Manual (IRM 25.1.2) and serve as the framework for both civil fraud penalty assertions and tax fraud referrals. No single badge of fraud conclusively proves fraud. Instead, the IRS evaluates the totality of circumstances — the more badges present, the stronger the inference of fraudulent intent. Revenue agents document badges of fraud throughout an examination, and if the evidence is sufficient, they can make a fraud referral to IRS Investigation. The IRS's Primary Badges of Fraud Income-Related Red Flags Badge What the IRS Looks For Why It Matters Substantial understatement of income Reporting significantly less income than third-party information indicates W-2s, 1099s, and bank deposits are compared to reported income Unexplained wealth or lifestyle Living beyond what reported income could support Home, cars, travel inconsistent with tax returns Failure to report entire sources of income Omitting a job, business, or investment entirely Different from underreporting — complete omission is more suspicious Unexplained bank deposits Cash or wire deposits that don't correspond to reported income Bank deposit analysis is a primary IRS investigation technique Dealing in cash Operating a cash-intensive...