The IRS uses statistical scoring, information matching, and pattern recognition to select returns for audit. Knowing what draws attention helps you stay compliant without fearing legitimate deductions.

Income that doesn’t match reported amounts is one of the biggest triggers. The IRS receives copies of your 1099s, W-2s, and other income documents. Their computers compare what you reported to what payers reported. If there’s a discrepancy, you’ll hear from them. This often leads to deeper examination if the numbers don’t reconcile easily.

Reporting losses year after year raises questions. The IRS expects businesses to make money eventually. If you’re claiming losses for three or more years in a row, they may decide your business is actually a hobby. Hobby expenses aren’t deductible against other income. Legitimate businesses do have bad years, but chronic losses invite scrutiny.

Cash-intensive businesses get audited more often. Restaurants, construction contractors, and retail stores with high cash sales draw attention because the IRS knows cash is easier to underreport than credit card transactions. If you’re in a cash business, meticulous records are your protection.

Large deductions relative to income trigger the IRS’s scoring system. Claiming $40,000 in vehicle expenses on $80,000 of revenue looks unusual. The return gets flagged because it falls outside normal patterns for businesses your size. That doesn’t mean the deduction is wrong, but you need documentation to prove it’s legitimate.

Claiming 100% business use of a vehicle is a common audit trigger. Very few people use a vehicle exclusively for business. If you’re claiming full business use and don’t have a second personal vehicle, expect questions. Keep a mileage log that shows actual business trips, dates, and purposes.

Misclassifying employees as independent contractors draws IRS attention. This often gets triggered by workers filing complaints or unemployment claims. The IRS loses revenue when workers are misclassified because no payroll taxes are withheld. If you’re using contractors, make sure they genuinely operate independent businesses and control how they do the work.

Round numbers throughout your return suggest estimates rather than actual records. A return showing $5,000 for supplies, $10,000 for vehicle expenses, and $2,500 for meals looks like guesswork. Real expenses have odd amounts. Round numbers signal that documentation might be lacking. This is why accurate small business bookkeeping matters so much.

Higher income increases audit probability. Returns reporting over $200,000 get audited at higher rates than those under $50,000. Self-employment income adds additional scrutiny because the IRS knows self-employed individuals have more opportunities to underreport.

Random selection does happen. Some percentage of returns are audited purely randomly as part of the IRS’s research program. You can do everything right and still get selected. This is uncommon but not preventable.

The best protection against audit problems is accurate records and documentation. Keep receipts, reconcile your accounts regularly, and report all income even if you didn’t receive a 1099 for it. If you’re audited and your records are solid, the audit usually ends quickly with no changes.

If you do receive an audit notice, don’t panic and don’t ignore it. Responding promptly with proper documentation resolves most issues. For anything beyond a simple correspondence audit, having IRS audit representation from an Enrolled Agent means someone who knows the process handles it on your behalf while you focus on running your business.