OK, now we have a different set of facts; now let me say up front that is unlikely that any tax is owed.
Here's how I analyze the situation based upon your revised facts;
At the time of your father's death, the title to the house remained in his name. He owned 100% of the home, but he retained the right to live in the home until his death. Based upon that, the house would have been included in his estate at the fair market value at his date of death. Based upon that, the tax basis of the house, in the hands of the estate is the fair market value at the date of death.
You'll need to tell me what the value was at the time of your father's death and what the house sold for -- ie. the number on the 1099-S.
Chances are you actually have a loss on the sale of the house; when an estate holds title to real estate acquired from a decedent, the real estate is consider an asset
held for investment;
So, you should be filing a tax return for the estate for 2011 to report the sale indicated on the 1099-S. There should be no tax due. There is most likely a loss, if nothing else due to the selling expenses related to the sale.
You didn't say what ID
number was indicated on the 1099-S.
Unfortunately, what this amounts to is a lot of paperwork, without much of a benefit
A couple of additional questions, did your father have a will and were there other assets in his estate? Was there a 1041 filed for the estate for 2010? Was a final personal return
for 2010 filed for your father?