1131. A charge on instruments.

Stamp duty is chargeable on instruments and not on transactions1. The liability of an instrument to stamp duty arises at the moment at which it is executed2 and depends on the law in force and the circumstances which exist at that time3. The character of the instrument must be ascertained by reference to its legal effect when it is executed4. The liability of an instrument to duty is not determined as at the time when the instrument is presented for stamping