The magazine found the latter point a cause for concern, insofar as credit card cheques incur higher charges than normal credit card use.
Moreover, the research found that 28 per cent of credit card users had chosen their particular cards just because they already had financial products with the provider.
Martyn Hocking, editor of Which? Money, said: "You should choose a credit card according to your spending habits and how much you repay each month.
"If you hold a card simply because you have another product with that provider or for reward scheme points then watch out - you're unlikely to be getting the best deal."
Only 21 per cent of those questioned said that they had selected a particular credit card because of an associated reward scheme.
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