07/17/2026
The IRS doesn't audit small businesses randomly. They run statistical models against every return looking for patterns — and almost every "audit trigger" is just a bookkeeping mistake someone left in their numbers.
The most common ones: round-number expenses (real expenses don't end in zeros), personal expenses categorized as business, 1099-NEC amounts that don't match reported revenue, S-Corp owners paying themselves an unreasonably low salary, and expense categories that fall way outside the normal range for the industry. The IRS knows what each industry's expense ratios should look like — they compare you against that benchmark and the outliers get pulled.
The pattern: every single one of these triggers is a bookkeeping problem. Round numbers come from estimating at year-end instead of categorizing in real time. Mixed personal/business comes from running one card for both. 1099 mismatches come from not reconciling. Clean monthly books prevent all of them.
The full list of 8 with how to fix each one: https://www.tidesbookkeeping.com/blog-bookkeeping-mistakes-that-trigger-irs-audits
https://www.tidesbookkeeping.com/blog-bookkeeping-mistakes-that-trigger-irs-audits