IRS Audit Red Flags in 2026: What the AI Is Looking For

You’ve just filed your return. Now comes the question that lingers in the back of every taxpayer’s mind: Am I going to get audited?

In 2026, that question has a different answer than it did just a few years ago. The IRS has deployed over 125 artificial intelligence and machine learning models — up from 54 in 2024 — to analyze returns, detect anomalies, flag fraud, and prioritize enforcement. Despite significant staff reductions (the agency is operating with roughly 77,000 employees, down from over 100,000), its technological capacity to identify audit targets has actually expanded.

At The Law Office of Pietro Canestrelli, we defend taxpayers across Temecula, San Diego, Riverside, San Bernardino, and throughout California in IRS audits — including those triggered by the agency’s new AI tools. Here’s what the algorithms are looking for and how to protect yourself.

How the IRS Selects Returns for Audit in 2026

The IRS uses a multi-layered system to identify returns for examination:

The Discriminant Information Function (DIF) Score

Every return receives a DIF score — a statistical measure of how your return compares to “normal” returns for taxpayers with similar income, occupation, and filing characteristics. The higher the score, the more likely your return contains errors or underreported income. The DIF system has been enhanced with machine learning in recent years, making it more accurate and harder to predict.

Automated Information Matching

The IRS’s Automated Underreporter Program (AUR) compares the income reported on your return against information returns filed by employers, banks, brokers, and other payers (W-2s, 1099s, K-1s). In 2026, this matching now includes the new Form 1099-DA for cryptocurrency transactions — meaning crypto income that was previously invisible to the IRS is now automatically flagged when it doesn’t match your return.

AI-Powered Pattern Recognition

The newer models go beyond simple matching. The IRS’s AI can identify patterns across millions of returns that suggest unreported income, inflated deductions, or improper credits. As we covered in our article on IRS AI enforcement, these models score returns approximately six times during each filing season.

The Top Audit Triggers in 2026

1. High Income (Over $400,000)

The IRS has explicitly stated that increased enforcement funding — even with workforce reductions — is focused on taxpayers earning over $400,000 annually. High-income individuals face audit rates several times higher than average. Complex partnerships and high-income pass-through entities are also priority targets.

If you’re a high-income earner in San Diego, Temecula, or anywhere in California, meticulous documentation is essential. Every deduction should be supportable, every income source reported, and every position defensible.

2. Cryptocurrency Transactions

With Form 1099-DA now live, the IRS has direct visibility into crypto trading for the first time. Key triggers include:

• 1099-DA showing gross proceeds with no corresponding cost basis reported on your return
• Large volumes of transactions inconsistent with reported income
• Failure to report crypto-to-crypto exchanges (which are taxable events)
• Answering “no” to the digital assets question on Form 1040 when exchange records show activity

If you have cryptocurrency holdings, read our 2026 crypto tax reporting guide for specific compliance guidance.

3. Employee Retention Credit (ERC) Claims

The IRS has made ERC enforcement a top priority, sending over 28,000 disallowance letters and launching 400+ criminal cases. Businesses that claimed the ERC — especially those that used third-party promoters — face a six-year audit window under the OBBBA. If you received ERC refunds, ensure your documentation supports the eligibility requirements. Visit our ERTC audit defense page for more information.

4. Large or Unusual Deductions Relative to Income

The DIF score flags returns where deductions are disproportionate to income. Common triggers include:

• Charitable contributions exceeding 3-5% of AGI (even though higher deductions may be legitimate)
• Home office deductions, especially when combined with a W-2 job
• Business meal and entertainment deductions that seem excessive for the size of the business
• Vehicle expenses claimed at 100% business use
• Large unreimbursed business expenses (though this deduction was eliminated for employees under the TCJA, some taxpayers still attempt to claim it)

5. Schedule C (Self-Employment) Losses

If you report business losses on Schedule C year after year — especially if you have W-2 income that offsets those losses — the IRS may challenge whether your activity is a legitimate business or a hobby. The “hobby loss” rules prevent taxpayers from deducting losses from activities not engaged in for profit.

Self-employed individuals and side-hustle workers should maintain contemporaneous records, show profit intent, and be prepared to demonstrate that the business is run in a businesslike manner.

6. Unreported Income from Cash-Intensive Businesses

Restaurants, salons, construction contractors, auto repair shops, and other cash-intensive businesses face heightened scrutiny. The IRS uses bank deposit analysis to identify potential unreported cash income — comparing deposits to reported gross receipts and investigating discrepancies.

If you own a cash-intensive business in Temecula, San Diego, Riverside, or anywhere in California, maintaining detailed daily records, separating personal and business accounts, and depositing all business receipts through your business account are critical audit defenses.

7. Foreign Income and Accounts

Unreported foreign income and failure to file FBARs and Form 8938 remain enforcement priorities. The IRS receives account information from over 100 countries under FATCA and bilateral tax information exchange agreements. If you have foreign accounts, read our FBAR and FATCA compliance guide.

8. Mismatched Income Reporting

Any discrepancy between the income reported on your return and the income reported to the IRS by third parties (W-2s, 1099s, K-1s, 1099-DA) will trigger at minimum a CP2000 notice — and potentially a full examination. In 2026, with the addition of crypto broker reporting, the volume of information returns the IRS receives has increased substantially.

9. Claiming OBBBA Deductions Without Eligibility

The new tips, overtime, auto loan interest, and senior deductions all have specific eligibility requirements and income phase-outs. The IRS is watching closely for improper claims — particularly the tips deduction (which requires qualifying occupation codes) and the overtime deduction (which requires FLSA-qualifying hours). Schedule 1-A is a new form, and new forms always attract scrutiny in their first year.

10. Math Errors and Inconsistencies

Not all audit triggers involve intentional underreporting. Simple math errors, transposed digits, incorrect Social Security numbers, and inconsistencies between forms (Schedule C and Form 1040, for example) can flag your return for review. The IRS’s automated systems catch these errors quickly, and while most result in correspondence audits rather than full examinations, they still create compliance headaches.

What to Do If You’re Audited

If you receive an audit notice, don’t panic — but do take it seriously. The steps you take in the first few days after receiving a notice can significantly affect the outcome.

• Read the notice carefully: Determine the type of audit (correspondence, office, or field), the issues being examined, and the deadlines for response.
• Gather documentation: The IRS notice will specify what records they want. Organize everything before responding.
• Consider representation: You have the right to be represented by a tax attorney, CPA, or enrolled agent. For anything beyond a simple correspondence audit, professional representation typically improves outcomes.
• Don’t volunteer information: Answer the IRS’s specific questions and provide the specific documents requested. Don’t hand over boxes of records or discuss issues not raised in the notice.
• Know your rights: You have the right to appeal any audit outcome, request a supervisor review, and petition the Tax Court if necessary.

For a deeper dive into audit preparation, read our comprehensive audit preparation guide and our article on how to avoid an audit.

How We Defend California Taxpayers in IRS Audits

At The Law Office of Pietro Canestrelli, we bring insider knowledge to every audit defense engagement. Our team understands the IRS examination process — the internal procedures, the criteria examiners use to evaluate positions, and the negotiation strategies that lead to favorable outcomes.

We represent individuals and businesses across Temecula, San Diego, Riverside, San Bernardino, and throughout California in:

• IRS examinations at every level — correspondence, office, and field audits
• Business tax audits including Schedule C, partnership, and corporate examinations
• California FTB audit defense — state audits that operate under different rules
• EDD payroll tax audits — worker classification and payroll issues
• IRS Appeals — challenging unfavorable audit outcomes

Received an audit notice? Contact The Law Office of Pietro Canestrelli before responding. The consultation could be the most important step in your audit.