The Financial Supervisory Service said that economically active Koreans held an average of 3.9 credit cards per person in 2013.
It marked the first time the number slipped below 4 since 2007, when it stood at an average of 3.7. The figure peaked at 4.9 in 2011, before sliding to 4.6 in the following year.
The number of credit cards in Korea stood at about 102 million at the end of 2013.
The FSS said the tally is estimated to drop to 90 million this year due largely to the growing use of debit and check cards because of more stringent credit card rules in the wake of data theft scandals.