12 When does a liability for duty arise?
(1) A liability for duty charged by this Chapter arises when a
transfer of dutiable property occurs.
(2) However, if a transfer of dutiable property is effected by a
written instrument, liability for duty charged by this Chapter arises when the
instrument is first executed.
(3) A liability for duty in respect of a dutiable transaction that is
charged with duty as if it were a transfer of dutiable property arises even if
the dutiable property is not in existence at the time that the transfer is
taken to have occurred, or the instrument effecting the transfer is first
executed, as the case requires.
(4) An electronic registry instrument is taken to be first executed
when it is first digitally signed by a subscriber (within the meaning of the
Electronic Conveyancing National Law