Two-thirds of Irish credit card users don't know their credit card's interest rate.
A survey by the Irish League of Credit Unions (ILCU) found there's a low level of understanding about rates and how the interest is calculated.
The study found over half of Irish consumers own a credit card, but 66% don't know how much interest they pay.
Almost a quarter surveyed believed they pay 5% interest or less, while 33% believed they pay between 18 and 24% in interest.
61% say they don't understand how credit card interest works.
The poll also revealed that the majority of purchases made using credit cards this year will be 'monthly ad-hoc purchases', while 12% will use credit cards for holidays.
65% of those surveyed will use their monthly income to clear their balance each month.
However, 18% will make only the minimum payment each month, while 9% are frequently unable to cover the minimum charge.
Head of Communications at the ILCU Paul Bailey, said “Credit card companies have a duty to make sure that their customers understand the product they are offering.
"I would encourage all members of the public to visit the Competition and Consumer Protection Commission's before applying for a credit card, and make sure that they are aware of the charges associated with a credit card account".