What is necessary for all returning international flights?

For all returning international flights, a printed customs form is essential for the customs declaration process upon arrival. This form is used by passengers to declare items they are bringing into the country, including goods purchased abroad, currency limits, and any items that might be subject to duty or restrictions. It helps customs officials assess whether any items need to be taxed or if additional scrutiny is necessary based on what the passenger has declared.

Having a printed customs form ensures that travelers can efficiently process through customs and helps maintain compliance with regulations regarding the importation of goods into the country. Passengers may need to fill out this form accurately before they land or upon arrival, which facilitates a smoother customs experience.

The other options, while related to travel procedures, do not encompass the necessary requirement for all returning international flights. For example, passport verification is generally required but is not explicitly the form's focus. Customs clearance by the captain pertains to the aircraft's arrival process rather than individual passenger requirements, and notification of arrival speaks more to operational procedures than the passenger customs process.