South Korean messaging giant Kakao has launched its digital bank, signing up more than one million account holders in its first few days.
Kakao Bank says that it would have opened even more accounts if not for delays caused by the amount of traffic it experienced.
Kakao, the operator of South Korea's largest mobile messaging app, was one of two firms to win approval in 2015 from the government to open the country's first digital-only banks.
The other provider, telco KT Corp, launched K-Bank in April but has not proved as popular as Kakao, signing up just 600,000 account holders.
Earlier this year, Kakao also got a boost from China's Ant Financial, which pumped $200 million into the Kakao Pay mobile finance subsidiary.