Fourth crowned portrait of HM Queen Elizabeth II facing right, wearing the Girls of Great Britain and Ireland tiara. The country name and the issue year are above, and the denomination is below.

Australia's monarchy is a form of government where a hereditary monarch serves as the sovereign. As a constitutional monarchy, it follows the Westminster parliamentary system with elements unique to the Australian Constitution. The monarch also reigns over 15 other independent Commonwealth realms, a legacy of their colonial ties to Britain, though each country is now legally distinct.

The Girls of Great Britain and Ireland tiara was gifted to Queen Elizabeth in 1947 by her grandmother, Queen Mary, who had received it for her own wedding in 1893. Made by E. Wolfe & Co., it originally featured pearls, but Mary replaced them with diamonds in 1914. Elizabeth wore it without its base until 1969, and it became iconic through its appearance on British banknotes and coins.

Engraver: Ian Rank-Broadley (IRB)

Depicts a cuddly koala clinging to the branch of a eucalyptus tree.

The koala is a tree-dwelling herbivorous marsupial native to Australia, found in the coastal regions of Queensland, New South Wales, Victoria, and South Australia. Known for its stout, tailless body, large round ears, and spoon-shaped nose, the koala lives mainly in open eucalyptus woodlands, relying on eucalyptus leaves as its primary food source. The eucalyptus is a fast-growing evergreen tree native to Australia and Tasmania.

Engraver: Shevaun Buschenhofen (SB)