Independent retailers continue to be dogged by chip and PIN-related problems, six months after the system became the standard method of shopper transaction.

In the latest survey of The Grocer Top 50 independent retailers, 64% said they had encountered sporadic or prolonged problems in processing payments.

One contact said he had encountered major problems with one merchant acquirer, so switched to another, dramatically reducing the incidence of problems. However, he added: "Since then, a number of missed transactions had to be reprocessed. We believe these problems have been caused by the change to chip and PIN."

Another retailer said he was still encountering cases of fraud because so many cards in the market were not chip and PIN compliant.