I'd like to know a.s.a.p. whether the Inheritance Tax threshold in respect of my father's recent death is likely to be �300,000 or �600,000. I am confused because I cannot seem to get my head round how Inheritance Tax works! My mother died 16 years ago and her Will ensured that all her assets passed to my father. No inheritance Tax was payable on her death. At the time of my father's death he owned his house but I don't know whether, while my mother was alive, they owned the house jointly or not, (my mother's last Will was made before the house was bought and so makes no special mention of the house) but perhaps this makes no difference? I'd be most grateful for any enlightenment, please.