As for security concerns raised by eased rules, Chung Ki-young, who handles electronic financial transactions in the IT & Financial Information Department at the FSS, said they distributed a "self-check list" to PGs, debit and prepaid card companies and other online settlement firms late last year to avoid security-related incidents.

"We will regularly look into them to see if they comply with the guidelines," Chung added.

Closer business ties between financial institutions and information technology companies have also given a big boost to the electronic financial transactions industry. The fintech promotion is among the policy priorities pushed by the current administration.   

The volume of the country's electronic financial transactions reached 109.8 trillion won, jumping 22 percent from 89.9 trillion won a year earlier. The volume more than doubled from 51.7 trillion won in 2011, according to the statement.

"As customers increasingly choose transactions on their mobile devices over shopping at offline stores, the electronic financial transaction market is expected to grow further," Chung said, without giving any projections about the market's future growth.

To allow small companies to offer online settlement services, the government has lowered the bar for them. Previously, they were obliged to have capital of 500 million to 1 billion won to enter the business but the limit was lowered to 300 million won, he said.

The number of electronic financial deals reached 15.67 billion in 2015, up 28 percent from a year earlier. (Yonhap)