New research from the Motley Fool website has shown that as much as a third of people are unaware of the interest they will be paying on a store card.
The fear is that these card holders are leaving themselves at an increased risk of facing mounting interest repayments - without actually realising it.
Added to this, the research also discovered that one in sixteen store card owners did not settle their account on time, meaning that they suffer the wrath of the large interest high street outlets charge shoppers.
It's now hoped that people will take more notice of the how much interest they will be charged on their plastic in wake of these findings.