Why can't I send or receive SMS on my Vietnamese SIM card in Nha Trang?

If you need to receive SMS, for example codes for online shopping, a traveler in September 2026 said he chose a plan that included SMS — around 160k, as he recalled. Codes from Lazada arrived on that number, but codes from Shopee for some reason did not.

Roaming instead of a local SIM drew skeptical comments in late July 2026: in one traveler's experience it is expensive and impractical — you activate a package, then separately add messaging apps, and then half of them turn out not to work. He eventually got a refund but advises not to bother.

The most common cause is a zero balance. In July 2026 participants explained that while the account is at 0, SMS does not work in either direction. The fix is to top up, for example with cash at the nearest FPT Shop, after which you can send messages again. In October 2026 the same question got the same answer.

To see how much credit is left on a Vietnamese SIM card, dial the USSD code *101# — participants recommended this in July 2026.