Most teahouses offer Wi-Fi services. If you want to use it, the teahouse will provide you with data for an extra fee But do not buy too much data at once. The data is valid for a particular place and time. Let us say you buy data in Namche. It is valid only for specific areas; other areas are not covered. The best option is to buy Nepalese SIM cards. It has reception even in Everest Base Camp and Kalapathar. For data, you can top up your credit according to your data needs and use the internet. To buy SIM cards, you must carry a PP, two photos, and a copy of your passport.