Credit card companies -- KB Kookmin Card, Lotte Card and NH Nonghyup Card -- have resumed operations after a three-month business suspension following the leak of personal data of some 140 million customers.
Starting with online services, the card companies are now able to issue new credit cards, extend loans and provide cash advances.
The firms will also promote a series of new card products with ample benefits, to attract new customers and make up for the loss incurred during the suspension period.
The ban is believed to have cost the companies tens of millions of dollars and millions of customers.
The country's biggest ever data leak was caused by an employee from a credit ratings agency stealing personal information, including identification numbers and bank account numbers, and selling it to an advertising company.
Meanwhile, financial authorities are planning to offer greater incentives when reporting of illegal practices of card firms when issuing new credit cards.
The Financial Supervisory Service said those who report of illegal methods to entice customers, such as issuing credit cards on the streets, or offering giveaways that exceed 10-percent of the annual membership fee, will be able to receive roughly 490 U.S. dollars in incentives, five times more than the original amount.
The reporting period will also be extended to 60 days from the current 20, and can be done through the Credit Finance Association, the Financial Supervisory Service, or individual card companies.
The financial authorities say they will inspect the credit card companies during the second half of the year, and if they conduct wrongdoings or irregularities they will be subject to heftier punishment.
Kim Min-ji, Arirang News.