The Australian Antarctic Territory, claimed by Australia on 1 December 1959,^[1] has used a postal system as its main point of contact since its establishment, due to its isolation. The territory covers over 5.8 million kilometres squared and currently has 5 stations, after Wilkes Station closed down in 1969. Each of the bases has their own post office that are run by Australia Post, who also controls stamp issues according to recent or important events within the territory. The history of the postage system dates back to the original post office within the territory, which first opened in 1955, which was in conjunction with a stamp release. The current system now combines new technologies with aged systems to create more efficiency, with recent stamp releases commending the history of the Australian Antarctic Territory and the Arts.

Australia has issued postage stamps for the Australian Antarctic Territory since 1957. All have been Antarctic themed, and are also valid for postage in Australia, so in practice, they are just Australian stamps with a different inscription. The Australian Antarctic Territory Act (1954) allowed for a postage system to be introduced in 1955, under the commonwealth and after the territory had commenced philatelic colonialism.^[1] The introduction of the system produced both a postmark and postcard, which could be used both on mainland Australia (for postage all over the country, not specifically to the Antarctic Territory) or from the Territory itself.^[1]

The first stamp issued specifically for the territory was a two-shilling blue stamp with a design of explorers and an Antarctic map. This was first issued in Australia on 27 March 1957 and in Antarctica on 11 December 1957. The original stamp design of 1957, which included a map of Antarctica, was seen as an “aggressive geopolitical assertion of territory”^[1] by the Australians, due to the map clearly marking the territory's boundaries.  This caused issues within Antarctica as a whole, as the “issuing of postmarks can only be performed by a sovereign state”.^[1] However, more than 23,000 letters were stamped with this postmark up until 1959,^[1] when several more stamps, such as the ‘Explorers at South Magnetic Pole’ and ‘Dog Sled and Team’ were released.^[5]

This stamp also features the flying of the Australian flag, in Vestfold Hills, Antarctica, on 3 March 1954,^[2] after a temporary landing in the Antarctic by Peter Shaw, Philip Law, and Dr. Arthur Gwynn.^[2] The flag flying image was converted to a drawing from a photograph donated by ANARE (Australian National Antarctic Research Expeditions), showing the three scientists next to the flag waving in the wind.^[2] This first stamp was sold at only two shillings per print.^[6]

The first commemorative stamp (as seen in the infobox) of the Australian Antarctic Territory was released on the 16th of October, 1961 to commemorate the 50th anniversary of the first Antarctic Expedition in 1911,^[5] led by the Australian scientist and explorer, Sir Douglas Mawson. This stamp features an image of Mawson on this expedition, surrounded by the words ‘Australian Antarctic Territory’. On the day of release for this stamp, Lady Francisca Adriana Mawson, the widowed wife of Mawson, received a “special album on behalf of the Postmaster General, Hon. C. W. Davidson”.^[2] The album contained a sheet of the minted stamps of Mawson, as well as past Australian Antarctic Territory that had also depicted him, such as ‘Explorers at South Magnetic Pole’ (1959).^[2] Similarly, an “imperforate block of four of the Mawson stamps was presented to Sir Thomas Playford, Premier of South Australia, for inclusion in the collection of the National Gallery of South Australia”.^[2]

Mail is delivered according to the transport schedule of the Australian Antarctic Territory from Hobart International Airport, Tasmania.^[6] All mail is consolidated at the Territory's Australian headquarters in Hobart, then consigned to transport, according to the schedule.^[3] There are several regulations around the postal system, in order to ensure that it runs smoothly due to the limited movement between the Territory and mainland Australia. Some of these include that all mail over one kilogram is considered to be cargo, whilst mail under one kilogram is considered air mail.^[3] All cargo mail leaves Tasmania with cargo flights, rather than on regular transportation flights.^[3]

Used stamps from the territory are usually found with either mainland Australia postal cancels, or first-day cover cancels as there is relatively little genuine mail from the bases.^{[citation needed]}

The Australian Antarctic Territory bases are:

• Casey Station
• Davis Station
• Macquarie Island Station
• Mawson Station
• Heard Island
• Cape Denison (Opened 2010)^[13][14]
• Wilkes Station (now closed)

Base cover sets are issued from Mawson, Davis, Casey and Macquarie Island stations.

All AAT mail will be cancelled with a postmark from one of these bases, though First Day Covers are now thought to be cancelled with the relevant base name at the Australian Philatelic Bureau, and not all bases are currently in use or permanently occupied.^{[citation needed]}