If you’re prone to to the tech-age ruse of scanning peanuts instead of pine nuts to scam savings at self-scan checkouts, think carefully next time you go shopping.

Supermarkets and law enforcement authorities are cracking down on shoplifting self-serve check outs in New South Wales.

Retailers such as Coles say they’re sick of being targeted by opportunists who lie about what they’re purchasing to get a discount or who try and avoid paying at all.

Anecdotes abound about shoppers who routinely type in onions in lieu of higher-priced items such as avocados, at self-scan checkout to extract a discount.

In one notable case, a couple in Scotland were charged with fraud for scanning two items worth 40 pence ($A0.67c) in lieu of the two TVs they left the shop with valued at £467 ($A780).

Detective superintendent Murray Chapman told media at a Coles outlet in Zetland, in inner-Sydney, on Thursday that the amount of the fraud was irrelevant to whether people would be prosecuted.

“No matter how small you think it is, even if it’s the avocado and you’re saving $2, it’s still shoplifting,” Superintendent Chapman said.