This service is available using SMS on SIM based mobile devices of major telecommunication carriers in 17 countries and regions, Thailand, Singapore, Malaysia, Indonesia, Vietnam, Philippines, Australia, India, Korea, China, Hong Kong, Taiwan, Myanmar, Cambodia, Laos, Guam and Japan (As of April 2018). The coverage is expanding.
The service is available in the roaming areas outside of the country of the above described SIM issuing carrier.