• Recent IRS enforcement has targeted high-income individuals, large corporations and complex partnerships.
• However, average taxpayers could still face an IRS audit for certain tax issues, experts say.

As Americans file returns this season, some worry about IRS audits amid agency efforts to ramp up service, technology and enforcement.

Recent IRS enforcement has targeted high-income individuals, large corporations and complex partnerships. But everyday filers could still face an audit — and certain issues are more prone to IRS scrutiny, experts say.

You don't want to face the "audit lottery," warned Ryan Losi, a certified public accountant and executive vice president of CPA firm Piascik.

Audit rates of individual income tax returns decreased for all income levels from tax years 2010 to 2019, largely due to lower IRS funding, according to a report from the Government Accountability Office.

The IRS audited 3.8 of every 1,000 returns, or 0.38%, during fiscal year 2022, down from 0.41% in 2021, according to a 2023 report from Syracuse University's Transactional Records Access Clearinghouse.

But many Americans could have a "false sense of comfort" about their personal audit risk, according to Mark Steber, chief tax information officer at Jackson Hewitt.

Here are some of the biggest IRS audit red flags. 

1. Missing income

For many taxpayers, missing income is easy for the IRS to catch because of so-called information returns, which are tax forms that employers and financial institutions send to the agency.

For example, you may have freelance income reported via Form 1099-NEC or investment earnings on Form 1099-B.

Steber said "mismatched data" is the No. 1 thing that gets taxpayers into trouble. "If you leave stuff off [your return], that could get a question," he said.

2. Unreasonable tax breaks

Another red flag could be excessive deductions compared to what's considered normal for your income level, according to Losi.

For example, if your adjusted gross income is around $100,000, but you're claiming itemized deductions — such as the charitable deduction — similar to million-dollar filers, that could raise eyebrows, he said.

"You need detailed substantiation," because if you can't prove you qualify for a tax break during an audit, you could lose the deduction, Losi said.

3. Round numbers

Accuracy is critical when filing your return and experts recommend using actual expenses rather than estimates for tax breaks.

When claiming four- or five-digit deductions, it's "very unlikely" your expenses will be round numbers, Losi said. "You're opening yourself up to be part of the audit lotto when you do that," he said.

4. Earned income tax credit

The earned income tax credit, a tax break for low- to moderate-income workers, has historically been scrutinized "because the refundable part attracts certain bad actors," said Steber.

It's a complex credit with a high "improper payments rate," National Taxpayer Advocate Erin Collins wrote in her 2023 Purple Book of legislative recommendations.

While higher earners are more likely to face an audit, EITC claimants have a 5.5 times higher audit rate than the rest of U.S. filers, partly because of improper payments, according to the Bipartisan Policy Center.

However, starting in fiscal 2024, the IRS said it would "substantially" reduce the number of correspondence audits, or audits by mail, for filers claiming the earned income tax credit.