Until earlier this week, section 127 of the Corporations Act required that documents executed on behalf of a company needed two company officers to physically sign the same document in wet ink. With companies that have a sole director who is also the sole secretary, only that person's wet ink signature was needed.
New laws (here) introduced by the Federal Government have amended those requirements and made it clear that documents executed on behalf of a company no longer not need to be in "wet ink" and do not need all officers to sign the same physical document.
A document signed in counterpart allows two or more identical copies of the same document to be signed by the parties, rather than requiring everyone to sign the same physical document. When all the parties have signed a copy, those copies when taken together are considered a single and validly executed document.
It is worth noting that, under the new laws, each copy or counterpart must include the entire contents of the actual document being executed, but does not need to include the signature of any other party. This requirement also extends to documents signed with electronic signatures.
There is however a requirement that there is some way to identify the person providing the electronic signature, as well as their intention about the contents of the document.