If the King or Governor-General is unavailable, who takes on their role?

Thanks for your question, Rohan!

According to Section 2 of the Australian Constitution, the Governor-General is appointed by the King to be His Majesty's representative in Australia. The Governor-General performs a number of constitutional, ceremonial and civic roles.

Should the Governor-General as the King’s representative be ‘unavailable’ for these duties, the Letters Patent—a document signed by Queen Victoria to establish the role of the Governor-General in Australia—allows for an Administrator or Deputy to be appointed to fill these roles on their behalf. An Administrator can be appointed at the request of Governor-General, Prime Minister, Deputy Prime Minister or most senior available Minister. The Governor-General traditionally appoints a Deputy (usually the Chief Justice) to declare open a new Parliament. Historically, State Governors have also been appointed as Deputies for the Governor-General.