Aust's Modern Treaty Law and Practice

Treaties may be amended by agreement between the parties. Bilateral treaties can be amended more easily than multilateral treaties. Bilateral treaties will sometimes include a provision on amendment but, in the absence of that, the parties will often simply proceed to amend the treaty by means of an exchange of notes, with provision concerning the entry into force of the amendment. Multilateral treaties too will often have express provision specifying amendment procedures. The chapter analyses various examples of these, including the use of supplementary treaties or protocols. If there is no such provision, residual rules are provided by Articles 40 and 41 of the Vienna Convention on the Law of Treaties.