Postby AnthonyR » Mon Mar 06, 2017 7:45 pm
First thing you need to check is whether the house was owned as joint tenants or tenants in common. If they were joint tenants your Grandad's share of the property would pass to your Nan on his death, regardless of the will.
Assuming they owned it as tenants in common, his half passing to your father would be worth £162,500 (less ~10% due to joint ownership) at death. Assuming there are no other substantial assets in the estate, this is well below the nil rate band and so would not be subject to IHT. IHT is only paid if the estate (plus any gifts in the past 7 years) exceeds £325,000.
You should have filed all the IHT forms before probate was granted though, so I would assume it was below the nil rate band, but check with the lawyer who assisted on the probate application if you had one.
Your nan should be aware that there could be some CGT on her share depending on how long she has been out of the property. This made more complex by the fact that she is non-resident as the gain would only accrue from April 2015.