My father gave his house to me and my sister before he died,if we sell the house will we have to pay capital gains tax?

If he truly gifted you both the house and retained no rights, then your basis is the basis your father had [purchase price plus capital improvements]. But most likely, and you will need an attorney to get more information, your father either retained an interest in the house legally, or he ratined it in actuality, in which case it would still be included in his estate and you would get a step up in basis equal to the FMV of the home the day he died. This is a question you truly need to see an attorney well versed in probate and estates. It’s worth the time and money to get a good reliable answer.

Eric Rothenberg