By Laura Dymock 7 News
In our cashless society, paying for your purchase can be as simple as tapping your card and you're done.
But using plastic instead of cash can cost you more if you also have to pay a card surcharge.
Laws were introduced in 2016 to limit how much surcharge a business can add on.
Around one per cent is fair for most credit cards.
However, the ACCC warns that hundreds of businesses across the country are slugging customers with illegal surcharges, despite the tough new laws.
For breaking the rules, online retailer Red Balloon was fined $43,000.Fitness First were fined $12,000, while Lloyds Auctioneers has been fined almost $40,000.
Europcar is one of the most recent examples, fined $350,000 for overcharging 63,000 customers.
"I hope the experience of Europcar sends a message more broadly that there are quite considerable fines possible in relation to this issue," the ACCC's Mick Keogh said.
7NEWS found one example of a children's ride that cost $2 with a 28 cent card surcharge - 14 times the legal rate.
"It's a bit frustrating for us because the law was introduced, it was introduced with quite considerable notice, and yet we find companies still not complying," Mr Keogh said.
"When we find companies in 2018 still ... flouting the law, it is very frustrating."
'When we find companies in 2018 still ... flouting the law, it is very frustrating.'
The ACCC says it is currently working through a large number of complaints about card charges and more than 750 small businesses have received warnings.
Its warning to customers? Always check before you tap.