yaySIM does not provide eSIM plans that include a local phone number or the ability to send SMS in Mongolia. Only data‑only eSIMs are available from this provider for the country.
Travelers can still use VoIP applications such as WhatsApp, Telegram or iMessage over the data connection for voice and text communication. However, some destinations may restrict or block certain apps or VoIP services, so it is advisable to confirm that the apps you need are accessible in Mongolia before purchasing a plan.