AUSTRALIAN credit card holders are being slugged with one of the highest interest rates in the world.

On average the 15 million cards in the country are being hit with a 21.99 per cent interest fee and in the past 15 years repayments have jumped 1000 per cent from $125 million to $1.3 billion.

In comparison, interest rates on credit cards in Japan sit at around 3 per cent, while borrowers in Europe pay between 9-11 per cent for the convenience of instant cash.

Commercial law expert at the University of NSW's Australian School of Business, Michael Peters, said the dominance of five major lenders - the four big banks and GE Money - led to the anomaly.

''They account for … just under 70 per cent of the credit cards used by Australians,'' Mr Peters said.

He said the current market was uncompetitive and compared credit cards to cars.

''The government would have to legislate for minimum safety standards, as well as wearing a seatbelt. The new laws that came into effect on July 1 installed a seatbelt, but it won't make people better drivers.''

He said Australians needed to be educated about the real cost of credit, especially in the area of minimum repayments.

On a debt of $1000, with a standard 2 per cent minimum repayment allowed by credit card companies it would take about seven years and nine months to pay off the loan. On top of the $1000 loan the borrower would pay $859 in interest.

And Mr Peters said about 13 per cent of Australians only ever paid the minimum.

Professor of marketing at the University of Sydney's Business School, Paul Henry, said credit card use has changed dramatically in the past 10 years.

''More people are rolling over their debt each month and never pay off the entire amount,'' Professor Henry said.

According to the Australian Securities and Investments Commission the average debt per cardholder is $4757, but 15 year ago this was just $2000.

Australia's love affair with plastic blew out credit card debt to over $50 billion for the first time last year and borrowers will be slugged with a record $1.31 billion in fees and an additional $36.3 billion of the total accruing interest.