A chargeable transfer is a transfer of value which is made by an individual but is not (by virtue of Part II of this Act or any other enactment) an exempt transfer.
A transfer of value made by an individual and exempt only to a limited extent—
is, if all the value transferred by it is within the limit, an exempt transfer, and
is, if that value is partly within and partly outside the limit, a chargeable transfer of so much of that value as is outside the limit as well as an exempt transfer of so much of that value as is within the limit.
Except where the context otherwise requires, references in this Act to chargeable transfers, to their making or to the values transferred by them shall be construed as including references to occasions on which tax is chargeable under Chapter III of Part III of this Act (apart from section 79), to their occurrence or to the amounts on which tax is then chargeable.