The smart move is to buy and install your eSIM while you are still at home on your own wifi. You pick a plan, scan one QR code, and the eSIM sits quietly on your phone. It does not start counting your data yet. It only kicks in when you land in Mongolia and the phone finds the Mobicom signal.
Doing this early means you walk out of the plane already connected. No hunting for a SIM counter, no swapping tiny plastic cards while you balance your bags. First check your phone supports eSIM. iPhone XS and newer, Google Pixel 3 and newer, and Samsung Galaxy S20 and newer all work. Your phone also needs to be carrier unlocked.
If you only need maps and messages on a short city trip, the 1 GB for 7 days plan at $3.88 is a cheap way to stay covered. It is the lowest price we offer.