Mobile phone users will be able to use two different numbers on one device through an eSIM service set to launch next month.

While mobile phones currently use USIM cards inserted into the device, eSIM phones such as Samsung Electronics' latest smartphone and some iPhones have the SIM pre-installed. 

Two telecommunications networks are displayed on eSIM phones, and users are able to select which number to use when making calls.

With consumer groups calling for a wider range of phone plans for the eSIM service, some low-cost service providers have introduced them, and KT, the nation's second-largest wireless carrier, also plans to offer a new plan exclusively for eSIMs.