The only way for the IRS to get after NON-FILERS is to take the documents filed with them: 1099s and W2s, .e.g., and create returns WITHOUT any deductions. IRS doesn’t know about your all your deductions… so they have assume none.
These returns are called “Substitute for Returns” or SFRs.
If you are self-employed, of course, you don’t receive any normal business deductions like mileage or fuel.
If you are married or have dependents the IRS files the return you as a single person. The point is: “SFRs” are big time wake up calls. You should file and pay your taxes. Even if you cannot pay you are far better off to file and discuss an installment agreement.
The SFR created liability is the same as any other liability. IRS job is to COLLECT. Remember, IRS does not write the laws. IRS is the collection arm for the U.S. Treasury.
Strategy… FILE CORRECTLY for past due returns. Don’t let it get to the point of levy or U.S. Tax Court.