K-Bank, a South Korean internet-only bank, on Thursday reported its first profit since its launch in 2017 thanks to a sharp increase in customers and interest income.

Net profit came to 22.4 billion won ($18.6 million) in 2021, a turnaround from a loss of 105.4 billion won a year earlier, according to the company's interim earnings report.

This marked the first annual net profit that the internet-only bank has posted since it was launched in 2017. K-Bank is controlled by a consortium of telecom giant KT Corp., Woori Bank and other companies.

The 2021 earnings stemmed mostly from a surge in the number of its customers and increased interest income.

K-Bank said the number of its customers came to 7.17 million as of end-December, up about 5 million compared with a year earlier.

Their deposits at the bank totaled 11.32 trillion won at the end of last year, sharply up from 3.75 trillion won a year earlier. Its outstanding loans also jumped from 2.99 trillion won to 7.09 trillion won over the cited period.

K-Bank earned 198 billion won in interest income last year, a 327 percent jump from a year earlier, the company said.

Its non-interest income came to 19.6 billion won last year, a turnaround from a loss of 10.2 billion won tallied the previous year.

K-Bank is now preparing to go public as part of efforts to raise funds to strengthen its foothold as a major financial platform. The bank aims to complete its initial public offering by the end of this year.

Internet-only banks here have basked in marked growth recently as customers tend to prefer banking through mobile phones rather than visiting offline branches, a trend more entrenched during the pandemic.

KakaoBank, K-Bank's bigger rival, went public on the country's main bourse last summer. (Yonhap)