Will my home SIM card offer free roaming in Thailand or Vietnam?

For most travelers from the US, UK, Europe, or Australia, 'free roaming' in Southeast Asia is highly unlikely. Countries like Thailand and Vietnam are typically outside the standard roaming zones for major carriers such as AT&T, Verizon, or Vodafone UK. This means you'd likely incur very high daily or per-MB roaming charges, which can quickly add up and drain your travel budget. SouthESIM offers a much more budget-friendly and predictable alternative, letting you explore places like Chiang Mai or Hoi An without bill shock.