Deductions & credits

@u0d4n7a0p: We need to end this conversation. You keep bringing up different scenarios and I don't know what you're really asking anymore. I will say it one more time. If you have a mortgage secured by your main home and use a portion of the proceeds for something other than the acquisition or improvement of that home, that portion of the mortgage is equity debt.  For a mixed-use mortgage, the equity portion of the debt is always paid down first. It doesn't matter if was for business or investment. Those costs are deducted elsewhere.