Retailers Association chief executive John Albertson said the findings might give retailers food for thought, but the answers to the survey questions posed were predictable.
"All things being equal, you'd say 'No, I'll go somewhere else [where there is no surcharge].' But all things aren't equal. It may be that that particular shop which is charging you an extra 2 per cent happens to be a couple of kilometres closer, therefore you are using less petrol."
Mr Albertson said the surcharge was not widespread in retail, but hotels, airlines and taxis were charging it "under one guise or another".
Retailers had to pay a service fee on credit-card usage and this had to be clawed back somehow to protect their "very fine margins", he said.
Mark Devlin, owner of shopping website showroom.co.nz, said he didn't charge a surcharge, and retailers who did were short-sighted.
"What we may lose in margin we definitely make up for in customer satisfaction and repeat purchase."