Most people choose to fly into Paro International Airport on a Bhutan Airlines flight from Bangkok, Kolkata and Kathmandu. Flights, however, can sometimes be delayed due to unpredictable weather in the Paro Valley. Always reconfirm your flight before departure, and check in early, because flights might occasionally depart before schedule, especially if the weather starts changing for the worse. You do not have to fill in a customs form on arrival unless you have imported goods to declare. Arrival/Baggage declaration card will be handed to you onboard but normally your travel agent will get all done for you before the trip.
You will be requested to fill baggage declaration card in arrival. This is to ensure that you are not carrying any of prohibited items to the country (see the list below A.) and some of the items you may need to show to the officer (see the list below B).