MIL died over 10 years ago. She left her house (which was in her sole name) in trust to her DC but stated that her partner, who I'll call FIL though they never married, could live there until his death.
Her will also stated that FIL could sell the house and buy another one with the proceeds. Upon FILs death the house would go to my DH and his brother.
FIL sold the house, bought another which he rents out and moved into a separate house with his new partner.
Don't have much contact with FIL but he sent a catch up email the other week and mentioned that the value of his estate might mean DH and his brother are liable for inheritance/CGT when he dies.
Can someone explain this? Why would his estate determine whether MIL's DC pay inheritance tax?