Addressing a letter to Australia requires a full address, which includes a postcode that can be found by searching on the Australia Post website. An address is typically 3-4 lines.
The top line of the address contains the recipient's name or business. The second line contains the number and name of the street or P.O. Box. The apartment or unit number is also included on this line. The third line should contain the place name or post office of delivery, state or territory abbreviation, and postcode. This line should be printed in capitals without punctuation or underlining, with the postcode listed last. For international mail, "Australia" should be written in capital letters on the bottom line.