When traveling on an international flight, each passenger must carry a valid passport and comply with the airline's boarding-gate arrival requirements. Airlines may also have rules for proof of onward travel, checked baggage limits and pre-arrival cabin disinfection.
Passport cards are not accepted on any international flight out of the United States. Many countries, including Mexico, require that travelers' passports be valid for at least six months; current validity stipulations for each country are available on the U.S. Department of State website. If the passport is not in the passenger's current name, the airline may ask for a marriage certificate or a notarized name-change authorization.
Some countries do not allow travelers to enter without proof of onward travel in the form of a return flight, boat ticket or ground transportation ticket. Depending on the country, the airline may require proof before allowing a passenger to board the international flight. In other cases, travelers must show proof at the destination country's immigration station.
Airlines often require passengers to arrive at the gate earlier for international flights than they must for domestic flights. On Delta Airlines, the minimum arrival time is 45 minutes prior to departure. For flights to Accra in Ghana, however, passengers must arrive at least 2 hours before the flight leaves. JetBlue, on the other hand, asks international passengers to check in at least 60 minutes in advance and arrive at the gate 20 minutes before takeoff.