How to check your own phone number on a Vietnamese SIM card?

If you bought a temporary SIM directly on the street in Nha Trang and don't know your number, first check which carrier it is — that determines the correct USSD code to reveal your number.

It's more reliable to buy a SIM at an official carrier store, such as Viettel, rather than from a street vendor — staff will tell you the number right away and explain how to check it later.

There's a detailed community post covering mobile connectivity in Vietnam, including how to check your SIM number.

To find out your Vietnamese SIM number, dial: Vinaphone *110#, Vietnamobile *123#, Mobifone *0#, Viettel *098#. The number will show up as a pop-up message on the screen.