IHTM04028 - Structure of the charge: what is the value transferred?

The value transferred by a chargeable transfer is calculated in a different way depending on the occasion of charge to Inheritance Tax

for lifetime transfers, the value transferred is the amount of the loss to the transferor’s estate, (IHTM04054)
on death, the value transferred is equal to the value of the deceased’s estate, immediately before death, (IHTM04044)
for a lifetime transfer of settled property in which a qualifying interest in possession subsists, the value transferred is equal to the value of the property in which the interest subsisted, (IHTM04093)
for relevant property trusts, the value transferred depends upon the actual occasion of charge. (IHTM04097)

Inheritance Tax Manual