SK Telecom Korea

SK Telecom, one of South Korea's largest carriers, offers eSIM roaming that extends to Vietnam and other Southeast Asian destinations. The service integrates with their existing customer base, so if you have an SK Telecom number at home, roaming activates smoothly without a new SIM.

Best for people traveling from South Korea who want continuity with their home carrier while abroad. The breadth of SK Telecom's network in Asia means routing and coverage tend to be reliable across the region, backed by one of the country's most established telecommunications providers.