Paragraph 2

This Convention shall also apply to any identical or substantially similar taxes which are imposed under the federal law of Australia or the law of the United Kingdom after the date of signature of this Convention in addition to, or in place of, the existing taxes. The competent authorities of the Contracting States shall notify each other of any substantial changes that have been made in the law of their respective States relating to the taxes to which this Convention applies within a reasonable period of time after those changes.