KakaoTaxi can now be used in Japan through a partnership with local counterpart JapanTaxi, Kakao has said, making it the cab-calling service's first expansion outside of South Korea.
The two apps will be synced, and JapanTaxi users can also use their apps to call cabs in Korea.
Kakao said it received multiple offers from other cab-calling apps globally, but with 5 million Korean tourists visiting Japan last year, it signed the deal with a Japanese vendor first.
JapanTaxi said travellers between countries were increasing 130 percent yearly and the move was to prepare for high traffic expected during the 2018 Pyeongchang Olympics Winter Games in Korea and the 2020 Tokyo Olympics.
KakaoTaxi is the most popular cab chauffeur app in Korea, with 1.5 million cab calls registered daily. Rival Uber's popularity is comparatively stale due to the negative press it received after trouble with the local government.
In March, Kakao invested 700 million won into connected car security firm Perseus.
Kakao is leveraging the dominance of Kakao Talk, South Korea's most used chat app, to expand services. It also enabled wire transfers to bank accounts in its chat app earlier this year.