The three credit card firms hit by recent massive data leaks may lose some 100 billion won ($93.6 million) in revenues due to a three-month business suspension ordered by the country’s financial regulator, data showed on Thursday.

Last month, the Financial Services Commission revealed that some 20 million clients’ personal data had been leaked from the three credit card firms ― KB Kookmin, NH NongHyup and Lotte ― as well as Kookmin Bank, which shared customer data with its affiliated card firm.

As punishment for the data breach, the card firms were barred from signing up new customers and offering new products and loan services starting Monday this week.

KB Kookmin Card estimated in a regulatory filing that it could lose some 44.6 billion won in operating revenue.

Lotte Card projected that the business suspension would incur some 29 billion won in revenue loss. NH NongHyup did not elaborate on its potential loss, but industry sources put the estimate at some 30 billion won.

The regulator is working on a set of measures that will better protect personal information handled by financial firms.

The measures under review include curbing financial firms from asking for “too much” personal information such as citizen registration numbers and strictly regulating information sharing among affiliates.

Under the proposed measures, clients will be given the choice to opt out of information sharing among affiliates and third parties. (Yonhap)