Privacy Commissioner Marie Shroff says a review is under way to decide whether credit companies in New Zealand will get greater access to people's financial details.
A reference group is considering whether the Credit Reporting Privacy Code - introduced in 2006 - should be changed.
Ms Shroff says New Zealand has a "negative" reporting system, whereby credit companies know mainly negative information such as whether someone has defaulted on a loan.
But credit reporting agencies are pushing for a "positive" system that would provide more information, including credit card balances and which institutions people had borrowed from.
Ms Shroff says supporters of the "positive" system believe it would stop people charging up several credit cards at once, but opponents say it would intrude into people's personal lives.