Mastercard has accused retailers of profiteering from fees that customers pay to cover the cost of using their cards.
The credit card company wants a cap on the amount shops can charge, saying some surcharges are more than what it costs to process the transaction.
Three years ago, the Commerce Commission allowed retailers to add a surcharge to credit card payments to cover the cost their banks charge them for processing the transaction - but the costs had to be reasonable.
Surcharging has since been picked up - mainly by airlines, parking companies and tourist operations - and Mastercard believes some costs are getting out of hand.
Mastercard New Zealand manager Albert Naffah said Australia began letting shops apply surcharges in 2003 and customers have suffered.
"In Australia, the Reserve Bank essentially gave retailers the ability to apply any level of surcharge, without any enforcement of a cap or a requirement that that surcharge is cost reflective.
"You saw in many environments, particularly where the merchant has some sort of market power - for example, the taxi industry or the airline industry - that the surcharges were significantly higher than the cost of accepting that payment."
Mr Naffah said Australia's central bank is now considering setting a cap on the fees. He said it is difficult to suggest a particular fee cap, due to the varying sizes and structures of businesses.
But the Retailers Association believes the vast majority of businesses do not charge for credit card transactions, so there is no need to cap how much customers have to pay.
Chief executive John Albertson said what customers are charged will vary depending on what power the shops have to negotiate a good processing fee with their banks.
"I think what would be fair and reasonable would be if you were charging anywhere from, say, one percent to three percent, depending on the size and scale of the business.
"If you're getting much over three to four percent, you're probably starting to get into the area where it's getting a little excessive."
Mr Albertson said shops - particularly those online - should warn customers before they start a transaction if there is going to be a surcharge.
