You open your mailbox and see an envelope with the IRS logo in the corner. Your stomach drops before you've even opened it. Will you owe more money? Do you need a lawyer? How long will this drag on?

An audit is one of the most stressful pieces of mail a person can receive — even when you've done nothing wrong. The good news: audits are rare, and most of them are avoidable once you know what actually catches the IRS's attention.

The Odds Are Low — But Not Even

Individual audit rates have been falling for years. The overall audit coverage rate dropped from 0.6% for Tax Year 2015 to just 0.3% for Tax Year 2021, according to the IRS Data Book for Fiscal Year 2025.

But "rare" doesn't mean you should play the odds as your only strategy to defend against audits. Your actual odds depend heavily on your income and how your return is put together. Here's how the odds break down:

Correspondence audits are handled entirely by mail — the IRS asks for documentation on a specific item. Field audits involve direct contact with an IRS agent and tend to be more thorough, more invasive, and more stressful.

5 Mistakes That Get Ordinary Taxpayers Flagged

Most audits aren't the result of bad luck. They're triggered by patterns the IRS's computers are specifically built to catch. Here are the most common ones:

1. Deductions that don't match your income.  Claiming a home office, meals, or a charitable gift that's much larger than what someone at your income level typically reports invites a second look — even when every dollar is legitimate.

2. Running a cash-heavy business.  Restaurants, salons, and other businesses that run heavily on cash have a well-documented history of underreported income, so the IRS pays closer attention to them by default.

3. Being self-employed with high expenses relative to income.  Independent contractors and small business owners who write off a high percentage of their income as expenses stand out, especially if profit margins look thin year after year.

4. Numbers that look off.  Reporting suspiciously round numbers, claiming a business loss several years in a row, or showing income that doesn't fit your line of work all raise red flags in the IRS's screening system.

5. Forgetting income the IRS already knows about.  This is the most avoidable mistake on the list. If a number on your return doesn't match what your employer or client already reported to the IRS on a W-2 or 1099, it's a near-automatic trigger for a correspondence audit.

What to Actually Do About It

The instinct to under-claim deductions out of fear is understandable — but it's the wrong move. You're entitled to every deduction and credit you legally qualify for. The goal isn't to claim less; it's to be able to back up what you claim.

• Keep documentation as you go.  Save receipts, mileage logs, and invoices for anything unusual or large relative to your income — not just at tax time, but as the expense happens.

• Double-check every income document.  Cross-check every W-2 and 1099 you receive against your return before you file. This single habit closes off the most common — and most easily avoidable — audit trigger.

• Don't leave money on the table.  Don't let audit anxiety talk you out of a deduction you're entitled to. A well-documented deduction that gets questioned is a quick conversation. A skipped deduction is money you didn't have to lose.

The bottom line: an audit letter is unsettling, but for most taxpayers it's also unlikely — and almost always traceable to one of the patterns above. Good records are the difference between a stressful audit and a five-minute one.

For Further Reading

https://www.irs.gov/statistics/soi-tax-stats-irs-data-book (IRS Data Book — source of the audit-rate figures)

https://www.irs.gov/businesses/small-businesses-self-employed/irs-audits