To enter Nepal; it is very easy, People of any nation can get visa upon arrival at Kathmandu international Airport (TIA) but they just have to have 6 months valid passport and two passport size photographs with a light background. Visa can be obtained only through payment of cash in the following currency: Euro, Swiss Franc, Pound Sterling, US dollar, Australian dollar, Canadian dollar, Chinese RMB, Hong-kong dollar, Singapore dollar and Japanese Yen. No return is necessary for American, European, British and Canadian Nationals.
Visas can be obtained on arrival at the airport and borders. Also one can have Nepal Visa in embassy of Nepal in your home country. You must pay in cash it cost USD 25 for 15 days, USD 40 for 30 days and USD 100 for 3 months. Visas valid for 15 days, 30 days and 90 days. Visas obtained from embassy is must be used within six months from the date of issue. Credit Card, Indian currency or Nepalese currency are not accepted for payment of Visa fee.
You will need 2 passport size photographs and relevant fees to apply. You can extend the visa in Department of Immigration in Kathmandu and Pokhara offices for total of 120 days.
Visa for Free
However, citizens of following countries cannot get visa on arrival at Immigration entry points of Nepal:
They need to obtain visa from Nepalese Embassies or Diplomatic Missions in their respective countries prior to their visit to Nepal. Rest of all national can get visa on arrival.
For Indian nationals do not require visa to enter into Nepal. For more information please visit to Nepal government official website http://www.nepalimmigration.gov.np/page/tourist-visa
For Online Application please copy the below link and paste to your browser, you will be directed to online form application online.nepalimmigration.gov.np/tourist-visa