What throws red flags to the IRS?

What Catches the IRS’s Attention?

It’s not paranoia—some financial moves really do raise eyebrows at the IRS. While no single factor automatically triggers an audit, certain patterns over time can draw scrutiny. One of the biggest red flags? Sudden and unexplained spikes in income, especially if your reported earnings jump dramatically from one year to the next without a clear reason. The same goes for reporting losses year after year—especially if you’re operating a side business. The IRS may start to wonder if you’re actually running a business or just using it to offset other income.

Another common trigger is consistently writing off large deductions that seem out of proportion to your income. Think luxury car leases, lavish travel, or home office claims that take up 90% of a 5,000-square-foot house. When deductions approach or exceed income, it raises questions. Also, using round numbers or estimates instead of precise figures—like claiming exactly $10,000 in charitable donations or estimated mileage—can look lazy or suspicious, even if unintentional.

Businesses that deal heavily in cash—like restaurants, salons, or retail shops—are naturally under more watchful eyes. The IRS knows cash transactions are easier to underreport. If your records show large amounts of unexplained cash deposits, that could prompt a closer look.

Don’t forget about foreign accounts. If you have overseas financial assets totaling more than $10,000 at any point in the year, you’re required to report them. Forgetting to file an FBAR (Foreign Bank Account Report) is a common misstep with serious consequences.

Finally, simple reporting errors—missing a form, skipping a required schedule, or transposing numbers—can also flag your return. The IRS runs automated checks, and even small mistakes stand out when systems are scanning millions of returns. Accuracy and consistency go a long way toward flying under the radar.

The bottom line? Honesty matters, but so does attention to detail. When in doubt, consult a tax pro—especially if your financial life is complex.