Half of consumers do not know how much they are paying in interest on their credit cards, according to new research from the Financial Regulator.
The regulator is urging credit card holders to learn more about the interest they are being charged on their credit card and to switch to cheaper providers.
The interest rates charged on some credit cards are among the most expensive in the country.
New research from the regulator shows that 45% of credit card holders surveyed do not pay their balance in full each month, making them eligible for interest.
Leaving aside enticing introductory rates, standard interest rates range from 9.4% to 18.9% on purchases. American Express charges the most expensive interest rate on the market.
Interest charged on cash withdrawals can be even more expensive, with Ulster Bank charging the most onerous rate of interest at 22.5% once its introductory offer rate has lapsed.
The regulator, which has produced a new booklet on how charging on credit cards works, urges consumers against using a credit cards for long term borrowing.
There is widespread concern about the level of personal debt in Ireland and the regulator is also urging consumers not to use one credit card to pay off debts on the other and not to re-use their credit cards until their debts are cleared.
More information is available on the regulator's website at www.itsyourmoney.ie