KakaoBank said on Tuesday that users of its conversational AI service surpassed 5 million a year after its launch.

After launching "AI Search" in May last year, KakaoBank introduced "KakaoBank AI", which integrates financial calculations, transfers and checks of financial information. It later expanded the service scope by applying AI functions to financial services such as "AI Transfer" and "AI Group Treasurer".

The service reached 1 million users within 3 months, 2 million within 6 months and 3 million within 8 months, before exceeding 5 million recently. That means about 10 new users used the service every minute after launch.

KakaoBank revamped its AI system through function upgrades and added features such as investment information and card-benefit searches. After that, customers using KakaoBank AI to search investment information such as stocks and funds rose by more than 10 times on a daily average basis.

It also added a feature that recommends follow-up questions that match the flow of the conversation. According to the company, satisfaction with answers rose to more than 90 percent and the dropout rate during conversations fell to about 1 percent.

KakaoBank plans to expand the application of AI technology across staff work and overall customer services. It will also strengthen personalized conversation functions for each customer through an additional revamp in the second half of this year.

A KakaoBank official said, "We improved accessibility so that anyone can easily use financial services through AI," and added, "We will continue to provide a differentiated financial experience through AI-based innovation."