The IRS does not read your return. A computer does.
It scores every return against what returns like yours normally look like. Sit too far outside the pattern and a human gets involved. That is the whole system.
Here is what pushes the score up.
1. You report a loss but your life says otherwise
This is the loudest one. Three years of losses on the return while you are buying property, financing cars, and moving real money through personal accounts.
The IRS runs matching. They see the 1099s, the mortgage interest, the interest income. When reported income cannot support the life on paper, that is a flag. It is also the flag that turns into a real audit most often, because it suggests unreported revenue rather than aggressive deductions.
If you genuinely had a loss year, fine. Document why. A bad year has a story. Three bad years while scaling does not.
2. Meals and entertainment that dwarf your revenue
Meals are deductible. Fifty percent, most of the time, when there is a business purpose and a person on the other side of the table.
The flag is proportion. If you did 180K in revenue and claimed 40K in meals, that is not a business that eats. That is a personal life running through a business card.
Same for travel. Same for auto. The computer knows what a normal ratio looks like for your industry code. Land far outside it and you get looked at.
Write off the real ones. Log who you met and why. Skip the rest.
3. Round numbers everywhere
50,000 in contractor payments. 10,000 in supplies. 5,000 in software.
Real expenses are not round. Real expenses are 47,312 and 9,847 and 4,206. When every line on a Schedule C ends in three zeros, you are telling the IRS you estimated instead of tracked.
Estimates mean no books. No books mean everything else on the return is a guess too. That is the message a round number sends, and it is worse than the number itself.
4. Crypto you did not report
The question is on the front of the return now. You have to answer it.
Exchanges report. The chain is public. The IRS has spent years building the tooling and they have already run enforcement campaigns off it.
Every sale is a taxable event. Every swap is a sale. Trading one coin for another is a disposal even though no dollars hit your bank. Spending crypto is a disposal. Getting paid in crypto is ordinary income at fair value on the day you received it.
Not reporting it is not a gray area. It is the easiest thing they catch.
5. Income that spikes or drops off a cliff
You did 90K, then 600K, then 120K. That pattern gets attention on both ends.
The spike year raises the question of whether the deductions attached to it are real. The drop year raises the question of where the revenue went.
Big swings happen. Businesses have launches and bad quarters. The fix is not to smooth the numbers. The fix is to have the records that explain them.
The pattern under the pattern
Every one of these is the same failure. Bad books.
Clean books produce specific numbers, sensible ratios, and a story you can back up. That is not audit proofing. Nothing is audit proof. It is being ready when the letter shows up.
If your books are not there yet, book a call.