The research found that some cards include features such as introductory enhanced rates, tiered earning rates and enhanced earnings at specific shops.
Discussing the findings, principal consultant and report author David Black said: "Despite their complexities, cash back credit cards offer a genuine return for card holders but are only appropriate for those people who always pay off their entire balance every month.
"This is another example in the credit card industry where consumers can take advantage of the offers by having more than one card and using each selectively to maximise cash back earnings."
Defaqto's research has been released after a study by Halifax found that UK shoppers could be paying over £20 in interest by not searching for the best credit card deals available to them.
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