The Australian one hundred dollar banknote was first issued in 1984 due to inflation. According to Reserve Bank of Australia statistics, the number of $100 banknotes in circulation in June 2005 was 149 million or 18.5% of all notes in circulation. The cash value for these notes was $14,924,000,000 or 41.9% of the total value for all denominations. Only the $50 note had more cash value in circulation. Updated figures to June 2008 were 176.9 million or 19%, and $17,690,000,000 or 42.1%. Again, the value of cash in circulation is more for the $50 note.

This can be explained by the fact that automated teller machines dispense $20 and $50 notes, but not $100 notes. Since the start of issuance there have been six signature combinations. Two other combinations were not issued. Since 1973, the main title identifying the country on banknotes has been "Australia". The denominations issued prior to 1973 used "Commonwealth of Australia".

Design

The paper issue has a portrait of Antarctic explorer Douglas Mawson, with a background of a mountain range with a geological strata format. A large diamond shape appears to the left of the main picture. Astronomer John Tebbutt is on the reverse, with a background of the observatory he built and a local church.

Security features

The paper design includes a watermark of Captain James Cook in the white field, and a metallic strip embedded in the paper to the left (on the obverse side) of the note. The same watermark was used in the last issue of the pre-decimal banknotes.