No foreigner is entitled to enter into and stay in Nepal without a valid visa.
Tourist entry visa can be obtained from Nepal Embassy/ Consulate or Mission offices abroad, or at the following immigration offices/points in Nepal:
Visa Facility: Multiple Entry
Duration: 15 Days, 30 Days and 90 Days respectively
Fee: USD 25, USD 40 and USD 100 respectively or equivalent convertible currency
Transit Visa for one day can be obtained from Nepal’s immigration offices at the entry points upon the production of departure flight ticket via Tribhuvan International Airport in Nepal, by paying USD 5 or equivalent convertible currency.
Before you start the visa process, please be sure to have following documents with you:
NOTE: Credit Card, Indian Currency, and Nepali Currency are not accepted as payment of visa fee.
A completed Online Tourist Visa form which is available at this LINK. You can also fill it at the airport on your arrival.