How the IRS's AI Engine Selects Returns for Audit — and What You Can Do to Stay Off Its Radar

A New Era of Enforcement Has Arrived

For decades, the IRS relied on a statistical scoring model called the Discriminant Information Function — commonly known as the DIF score — to rank returns by their audit potential. A human examiner would then review high-scoring returns and decide whether to investigate further. That process was methodical, but it was also slow and limited in scope.

That era is drawing to a close. The IRS has publicly acknowledged significant investments in artificial intelligence and machine learning as part of a broader modernization effort, accelerated in part by additional funding secured through recent federal legislation. Today, automated systems can cross-reference a single tax return against third-party data sources, historical filing patterns, industry benchmarks, and even information reported by other taxpayers in related transactions — all within seconds.

For the average filer, this shift carries real consequences. The technology does not get tired, it does not miss patterns, and it does not give the benefit of the doubt. If your return contains combinations of entries that statistically correlate with underreporting or overclaiming, an algorithm will find it.

What the Algorithms Are Actually Looking For

To protect your return, it helps to understand what the IRS's automated systems are designed to detect. While the agency does not publish its full algorithmic criteria — for obvious reasons — tax professionals and former IRS officials have identified several consistent triggers.

Disproportionate deductions relative to income. Machine learning models are trained on enormous datasets of returns filed within the same income range and industry category. If your claimed deductions deviate sharply from the statistical norm for your peer group, the algorithm flags the discrepancy for review. A sole proprietor reporting $80,000 in gross receipts but claiming $60,000 in business expenses, for example, sits well outside the expected range for most industries.

Rounded numbers throughout the return. Legitimate expenses almost never land on round figures. A Schedule C that lists $5,000 for supplies, $3,000 for travel, and $2,000 for advertising raises a quiet alarm. Real receipts produce irregular numbers. Consistent rounding suggests estimation rather than documentation.

Losses from a Schedule C business claimed year after year. The IRS's hobby loss rules exist precisely because personal activities are sometimes disguised as businesses to generate deductible losses. Automated systems are calibrated to detect multi-year loss patterns, particularly when the activity aligns with common hobbies or when the taxpayer has substantial W-2 income that would benefit from an offsetting loss.

Home office deductions that appear inflated. Since the pandemic normalized remote work, home office claims have surged. The algorithms know this — and they also know the typical square footage percentages that reflect legitimate use. A claim that represents 40 or 50 percent of a home's total area draws scrutiny, especially when the property records accessible to the IRS suggest the home is modest in size.

Cryptocurrency transactions that don't reconcile. The IRS now receives Form 1099-DA data from digital asset brokers, and its systems are designed to match those figures against what appears — or conspicuously does not appear — on a taxpayer's return. Unreported or inconsistently reported crypto activity is among the most reliably flagged categories in current enforcement priorities.

Cash-intensive businesses with unusually low reported income. Restaurants, contractors, and other businesses that handle significant cash are compared against industry revenue benchmarks. When reported income falls well below what comparable businesses in the same market typically generate, the gap itself becomes a data point.

The Documentation Discipline That Protects You

The most important thing to understand about algorithmic audit selection is this: the system cannot evaluate intent, context, or explanation. It can only evaluate the numbers on the page and how they compare to patterns in its training data. Your defense, therefore, is not an explanation — it is documentation that makes your numbers make sense before anyone asks.

Maintain contemporaneous records, not reconstructions. A mileage log created in December to cover a full year of driving is legally fragile and factually unconvincing. The IRS expects records made at or near the time of each expense. Digital tools — dedicated mileage tracking apps, receipt-scanning software, and cloud-based bookkeeping platforms — make this standard achievable without significant effort.

Separate business and personal finances completely. Commingled accounts create ambiguity, and ambiguity invites scrutiny. Dedicated business checking accounts and credit cards produce clean, auditable records that allow a tax professional — or an IRS examiner — to trace every deduction directly to a specific transaction.

Attach context where the numbers are unusual. If your business legitimately generated a loss for the third consecutive year because of a documented market disruption or a capital investment cycle, that story should be told through your records, not improvised during an audit. A well-organized file of invoices, contracts, and bank statements can transform an anomalous-looking return into a defensible one.

Work with a qualified tax professional when your situation is complex. Algorithmic review does not end at selection — it informs the direction of the examination itself. A return prepared by a credentialed tax professional, with consistent treatment of recurring items and clear documentation attached, signals to both automated systems and human examiners that the filing was prepared carefully.

What to Do If You Are Already Selected

Receiving an IRS notice does not mean you did anything wrong. A significant percentage of audits — particularly correspondence audits conducted by mail — are resolved in the taxpayer's favor when adequate documentation is provided. The key is to respond promptly, address only what is asked, and avoid volunteering information that extends the scope of the examination.

If you receive a notice, contact a tax professional before responding. An enrolled agent, CPA, or tax attorney can review the specific items under scrutiny, assess your documentation, and communicate with the IRS on your behalf. Attempting to navigate an audit without professional guidance frequently results in expanded examinations and less favorable outcomes.

Filing Smart in an Algorithmic Age

The IRS's adoption of artificial intelligence is not a reason to fear filing your taxes — it is a reason to file them carefully. The taxpayers most vulnerable to algorithmic scrutiny are those who estimate rather than document, who claim deductions without substantiation, or who allow inconsistencies to accumulate across their returns year after year.

At RyanTax Pro, we work with individuals and small business owners to build filing strategies that are both aggressive in capturing every legitimate deduction and disciplined in maintaining the records that support them. The goal is not to hide from the IRS's technology — it is to file a return that holds up under any level of review, automated or otherwise.

If you have questions about how your current filing practices would appear to an algorithmic review, or if you want a professional assessment of your documentation habits before next tax season, our team is available to help you file with clarity and confidence.