The 10 shilling note was issued May 1, 1913, in Melbourne, in the presence of the then prime minister Andrew Fisher and governor-general Lord Denman. The note was presented by Fisher to Judith Denman, the five-year-old daughter of the governor-general.
The note with the serial number M000001, was found tucked away in a book in England in 1999, nearly 12 years after Judith's death, and was acquired by a private collector in Sydney for AusD 1million (GBP 660,000) in 2000.
Coinworks, which deals in rare coins and notes and is handling the sale this time. They said that the note symbolised one of the most important periods of Australia's history - the establishment of the Commonwealth of Australia in 1901 and the subsequent evolution of nationhood.
The chief executive officer of Coinworks, Belinda Downie, says the expectation is that this time, the note will sell for at least AusD 3.5 million.
The note will be displayed at the World Stamp Expo later this month, in a hand-crafted wooden box worth AusD 10,000. It is believed that only about 20 of the 10 shillings notes remain in circulation.