Originally Posted by
Platcomike
Yes, but keep in mind the return text (Thailand to your US number that happens to be in Thailand) would likely incur a charge to the Thai phone as if they called any US number. No free text for them just because you happen to be there on a free roaming plan.
Highly suggest since data is free to have other party in other country you are in to use Whatsapp (or iMessage if both on iOS devices). Avoid messaging charges for not just TMO side but other party texting you. (other options of course with LINE and WeChat)