Deductions & credits

the issue is for those of us who flip multiple houses ("dealers") with sole member llc filing a 1040 schedule c, how does a person differentiate the houses on a single line?  I just got hit with a $377,000 IRS bill because IRS could not tell which properties are included because I use a single EIN. 

 

Additionally, on the gross receipts, I added up all resale prices MINUS all purchase prices, then went through and total each deduction.    There has to be a form to distinguish the individual properties to roll up into the schedule C line 1.     I am researching this now, and have called in for LIVE support to get an answer.