In short:
Small businesses say they are increasingly being scammed with high-quality counterfeit notes.
The Australian Border Force says there has been a dramatic spike in the number of counterfeit cash seizures.
What's next?
Local businesses in the Illawarra are training employees to use blue-light machines and keep an eye out for fake cash.
When Thirroul business owner Calvin Gorsuch's employee was handed a $100 bill by a customer last weekend, they instantly knew it was a fake.
That was because his business, Ohana Home, runs every bill under a blue-light machine.
"So we picked up that it was fake," Mr Gorsuch said.
"They were adamant that it was genuine, but we kept refusing it, and then they left."
Mr Gorsuch said he put the safeguard system in place after the business was stung with a counterfeit $50 note last December.
Fake notes hit small businesses
Later that same day, neighbouring shop owner Adrian Erdedi's employee was counting the till and noticed something "a little bit odd" about a $100 bill.
"Eventually we identified that it was a fake note taken by one of the other staff members during the day," he said.
The business owners both said more local traders were reporting the same issue.
Mr Erdedi said he posted about the incident on a local Facebook page, where he was overwhelmed by responses from other business owners across the Illawarra.
"There's been a lot of people coming out saying they've had the same notes coming through," he said.
"From what I've heard, there are also $20 notes involved now."
High quality deceptions
In the past financial year, the Australian Border Force (ABF) made 700 detections of counterfeit cash entering the country, intercepting fake notes with a value of $6 million.
That was more than 50 times the number of counterfeit currency imports detected the previous year.
In a statement issued last month, the ABF said there had been "a concerning improvement in the quality of counterfeit notes".
Mr Erdedi said he could not believe how realistic the fake $100 note was.
"It could have easily been missed if you're not looking for these specific things on the note," he said.
"Once we compared it with another $100 note, you could see the difference, but you had to look really closely to find those little defects."
Mr Gorsuch said in 10 years working in retail, he had seen the quality of fake notes improve substantially.
"In the past when we got fake notes, they were paper-based, and if you scrunched it, it wouldn't pop back," he said.
"The ones now are a polymer, so to the touch they feel more real.
"The colour seems to be the distinguishing factor."
New measures
In Australia, it is against the law to make, possess or knowingly use counterfeit money.
The maximum penalty for producing fake banknotes is 14 years in jail.
On its website, the Reserve Bank of Australia (RBA) advises that suspect banknotes should be reported to police and that counterfeits had no value, meaning scammed businesses would not be reimbursed.
Mr Gorsuch said fake cash also ended up costing local businesses at a time when cost-of-living pressures were already biting.
After the first scam in December, his employees had been trained to verify every note that came through using a blue-light scanner near the till.
“Every bill we accept we quickly wave it under the light and then that usually shows the invisible UV marks, and then we know it's a genuine note,” he said.
Polymer notes issued by the RBA after 2016 also have a serial number and date of manufacture that light up under blue light.
Mr Erdedi said he had also ordered a blue light and was now training employees to check every note.
