More than four out of 10 adults are yet to have all their debit and credit cards converted to chip and pin technology, a survey has suggested.
The survey, by card issuing firm Retail Decisions, also found that 9% of people had no chip and pin card.
Chip and pin cards have been credited with a recent cut in card fraud.
However, the Association of Payment Clearing Services (Apacs) said 127 million out of 141 million cards in the UK were now chip and pin.
Chip and pin cards aim to cut fraud by including a smart chip, which can store more information than the usual magnetic strips, and also by having users verify transactions by keying in a pin number rather than signing a receipt.
Over the past two years card issuers have been busy replacing all credit and debit cards in the UK.
Last October, figures from Apacs, which is co-ordinating the roll out of chip and pin, showed that fraud involving the stealing and counterfeiting card fraud had fallen 29% during the previous twelve months.
But according to Retail Decisions, there is a significant minority of consumers being denied the protection of chip and pin.
In total, the group found that 59% of consumers had all their chip and pin cards replaced.
"These figures indicate that there is still some way to go in order to ensure that everyone has the necessary replacement cards and pins," Carl Clump, chief executive officer of Retail Decisions said.
Sandra Quinn, spokeswoman for Apacs, admitted to BBC News that some companies had been slow to roll out chip and pin.
"There are some card issuers that have lagged behind and have only recently started to roll out chip and pin.
"However, crucially, our research shows that the vast majority of people have one or more chip or pin cards in their purse or wallet," she added.