A Waikato bakery is one of the latest to fall victim to counterfeit money amid a series of cases in the area.
Hundreds of dollars of counterfeit notes have been found in Waikato, with retailers being warned to keep a sharp eye out during the Christmas rush.
Since October, police say there have been seven incidents with alleged fake notes, including $50, $20 and $10 notes.
They have been reported across Waikato, including Hamilton East, Te Rapa, Frankton, Te Awamutu, Beerescourt, and Paeroa.
Kath Ung, owner of the Golden Pie Bakery and Cafe in Hamilton, said a man came into her shop early Monday morning and bought a sweet muffin with a $100, asking for change.
Looking closer, she could tell the note was a fake, Ung said.
"The paper is different, because the real note is like a bit plastic, it's not like paper paper, but this one is like a newspaper," she said.
"The colour is like light pink not dark pink, and it's a bit longer."
The man was given more than $90 in change, Ung said.
"I can't do anything with that [$100] note, I lost the money."
The man had been acting suspicious as she went to the bank to get change, Ung said.
"He look a bit [rushed] ... he couldn't stay in one place, his reaction showed that he 100 percent knew it was a fake note."
When Ung reported it to police, they told her to come in and drop the bill at the station.
"I've got no time to do that stuff," Ung said.
She said she was not happy after being scammed, given her and her staff work hard to earn a living.
"We're working so hard, I have to get up at like four in the morning to make the pies," she said.
"I'm not so happy though, we're working so hard and then they use that fake note on us and get our money.
"Everything is going up, and we try to work hard for the cost of living," said Ung.
Signs of counterfeit money
Waikato Prevention Manager Inspector Hywel Jones told Checkpoint people should check every note they were handed.
There are some security features - which help distinguish fake notes - on the two types of banknotes in circulation at the moment.
"The first one has a bird at the lower left front. And if you move that back and forth, you should see a rolling bow of color, as it's tilted and you can hold it up to the light and you'll see a fern in the centre of the bird," Jones said.
"The second older style of banknote has got a small oval window at the front right and holding it up to a light will show a watermark of the queen to the left of that window.
"And finally, for those retailers, I suppose who've got a UV torch or black light, both styles have a patch that shows the denomination that glows which is located on the front left of the note."