These days, most inventions are developed in the research departments of large companies. The company is the entity that applies for the patent. Also, an inventor may assign or sell his invention to somebody else. In that case, it is the assignee or buyer who applies for the patent. If you intend applying for a patent, you would be well advised to hire a patent attorney to act for you.
Patent law is complex.
The invention itself is often technically complex. The Patents Office, now known as IP Australia, is situated in Canberra. There is a branch office located in each of the State capital cities. The forms required to apply for a patent can be obtained from any of the Patent offices. These charges do not take into account any professional fees payable to a patent attorney.