Some of the UK’s wealthiest families were landed with retrospective tax bills in the region of £1.4 million on lifetime gifts, according to annual figures from a Freedom of Information (FOI) request by RBC Brewin Dolphin.

The families tried to make use of a rule allowing individuals to make gifts of unlimited value which become exempt from inheritance tax if the giver survives a further seven years, known as a “potentially exempt transfer” (PET).

But the FOI requ...