The number of smartphone-based banking service users rose 3.6 percent from three months earlier to 77.3 million as of end-March, according to the Bank of Korea. South Korea has a population of 51 million, but some people have multiple smartphones.

Banks have cut the number of their brick-and-mortar bank branches, a move that poses a challenge to some older people who are not familiar with smartphone banking services.

"Technological innovation is a trend that we cannot go against," BOK Gov. Lee Ju-yeol said in a meeting with heads of major banks in Seoul.

He asked heads of major banks to narrow the digital divide for seniors as banks expand innovation in digital finance. (Yonhap)