Hello, I am Keith, one of the experts on Juat Answer, and pleased to be able to help you with your question.
UK Inheritance Tax (IHT) kicks in at 325K and is at a 40% flat rate. The 325K is inflated by any inter spousal or charitable bequests and if the latter are 10% of more of the deceased's estate the rate of tax falls to 36%.
The 325K limit will progressively rise from 2017 to 2020 to one million, but only for the family home bequeathed to children.
That is about as far as I can go without more information from you.