Kolet does not provide a Vietnam eSIM that includes a local phone number or the ability to send or receive SMS. All of Kolet’s Vietnam plans are data‑only, so travelers can use the connection for internet access but will need to rely on VoIP or messaging apps such as WhatsApp, Telegram or iMessage for voice and text communication. Those apps typically function over the data connection; however, some destinations may block or limit specific VoIP services, so it is wise to verify that the apps you need are accessible in Vietnam before proceeding with a purchase.