Changes to the National Consumer Credit Protection Act 2009, which became law in the first quarter of 2018, will have a noticeable effect on the credit card sector, says a senior lawyer. The changes mean a consumer's suitability for a credit card contract or credit limit increase must be assessed according to their ability to pay the credit limit in full within a certain period determined by ASIC - as John Denovan and his colleague and Rachel Walker explained in a note to clients of their law firm, Dentons. Denovan suggested the regulator is proposing to prescribe a period of three years for responsible lending assessments for new credit card contracts or credit limit increases.The final instrument is due to be released sometime this month or in September. Such a move would contradict the new ABA Banking Code of Practice, which states that subscribing banks will assess a customer's ability to repay the amount of the credit card limit within a five year period. The prohibition on charging interest retrospectively on interest free periods may be the catalyst for major changes to credit card products.  Most cards offer up to 56 days interest free on purchases so long as the full balance is paid each month.  However, according to Canstar, products are not uniform.  There are credit cards that have no interest-free days so that interest is charged on all purchases, regardless of whether or not the balance is paid in full each month.   There are also lenders which only charge interest from the statement date as distinct from the purchase date. Apart from the inconsistencies, Denovan suggested that the question to ask is: "Will most or all interest free periods disappear when the law changes on 1 January 2019 for new and existing cards?" "Coming on top of a major reduction in points earned on many cards, the loss of interest free periods may result in credit cards being abandoned by many customers in favour of debit cards and other payment methods," he said. Both credit and debit card programs may face further challenges if government adopts the recommendation by the Productivity Commission that all card interchange fees be abolished by the end of 2019.