You’ve probably seen one. Maybe you even have one tucked away in a birthday card or a "rainy day" jar. But honestly, for most of us, the 100 dollar note in Australia feels a bit like a cryptid. It exists, the Reserve Bank of Australia (RBA) says there are millions of them, yet they rarely seem to make an appearance at the local self-checkout.
The "Green Ghost," as some call it, is the highest denomination in our currency. It’s a fascinating piece of plastic, packed with more tech than the first Apollo moon mission and carrying the faces of two Australians who basically conquered the world in their respective fields.
Who are those people anyway?
If you pull out a 100 dollar note in Australia, you’re looking at Dame Nellie Melba and General Sir John Monash.
Melba wasn't just some singer. She was a global superstar long before Instagram. Born Helen Porter Mitchell, she took the stage name "Melba" after her hometown, Melbourne. She was the first Australian to achieve international fame as a classical musician. On the note, you can see her in costume as Rosina from The Barber of Seville. There's also a tiny image of Her Majesty’s Theatre in Sydney, where she performed a massive homecoming tour in 1902.
Flip it over and you meet Sir John Monash. He was a polymath—engineer, lawyer, and one of the greatest military commanders in history. During World War I, his leadership at the Battle of Hamel was so precise it's still studied by soldiers today. The note includes a scene of Australian field artillery attacking the Hindenburg Line and a small portrait of John Simpson Kirkpatrick (the guy with the donkey at Gallipoli).
The security tech is actually insane
Australia was the first country to use polymer (plastic) for its money back in 1988. We grew tired of paper notes turning into soggy confetti in boardshorts. The current "Next Generation" 100 dollar note in Australia, released in late 2020, is basically a fortress.
- The Top-to-Bottom Window: This is the most obvious feature. It's a clear strip that runs the whole height of the note. Inside, there's a 3D fan that looks like it's popping out at you.
- The Masked Owl: If you tilt the note, you'll see an Australian Masked Owl. Its wings move and change colour. It’s not just pretty; it’s incredibly hard for a desktop printer to replicate.
- Microprinting: Grab a magnifying glass. There are tiny excerpts from Melba’s autobiography, Melodies and Memories, and a letter Monash wrote.
- The Rolling Colour Effect: There’s a patch on the corner that shows a rolling bar of colour when you tilt it.
Check the edges too. There are five slightly raised "tactile" bumps on each long edge. This helps the vision-impaired community distinguish the hundred from the fifty, which only has four.
The big mystery: where is all the cash?
Here is the weird part. There are roughly 400 million $100 notes in circulation. That’s about 15 for every single person in the country. If that's true, why don't we see them?
Economists call this the "currency paradox." Even though we use "Tap and Go" for everything from a $4 latte to a $2,000 laptop, the demand for high-value notes is at record highs.
Where is it? Mostly in "hoards." People keep it under mattresses or in safes as a store of wealth, especially during times of economic uncertainty. Some of it is likely involved in the "shadow economy"—cash-in-hand jobs or more illicit activities—which has led to occasional calls from some politicians to scrap the note entirely. India did something similar years ago to fight corruption, and it caused total chaos. For now, the RBA says the green note is staying right where it is.
How to spot a fake in 5 seconds
While Australian notes are world-class, fakes do pop up. Don't rely on just one feature.
- The Feel: Polymer feels like plastic. It shouldn't feel like paper or fabric. If you scrunch it, it should bounce back.
- The Star: Look at the small circle with the diamond patterns. Hold it up to the light. The patterns on the front and back should align perfectly to form a seven-pointed star.
- The Window: It should be part of the note, not a piece of tape stuck on.
- UV Light: If you happen to have a UV torch (a 365nm one works best), the serial number will glow, and a hidden image of the masked owl and golden wattle will appear.
What to do with your hundreds
If you’ve found an old paper 100 dollar note in Australia (the blue one with Douglas Mawson), don't throw it away! It’s still legal tender. While most shops might look at you like you're from the 19th century, you can take it to any bank and they’ll swap it for a modern one at face value.
Collectors, however, might pay more. A "first prefix" note (look for serial numbers starting with "AA") or a "last prefix" in perfect condition can fetch hundreds or even thousands on the secondary market.
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To keep your money secure, always check for the clear window and the "rolling" colour effect when accepting large cash payments. If you suspect a note is fake, you're actually within your rights to refuse it. Just handle it as little as possible, put it in an envelope, and take it to the police.
Next time you hold a 100 dollar note in Australia, take a second to look at the owl and the opera singer. It's a lot more than just a piece of green plastic.