A passport is required for all international travel. If you're traveling anywhere overseas, you need a passport to board an international flight and to enter the country. Passport cards will not be accepted as form of I.D. for international air travel.

To board an international flight in 2026, you need a specific set of "API" (Advance Passenger Information) and physical documents. First and foremost is a valid Passport (usually with 6 months' validity). Second, you must have proof of your Visa or Travel Authorization (like an ESTA for the US, an ETA for the UK, or an ETIAS for the EU). At the check-in counter or kiosk, you will need your 6-digit PNR (Booking Reference) or your 13-digit E-ticket number. Many countries now require "Digital Passenger Declaration" forms or proof of return/onward travel before they allow the airline to issue a boarding pass. While COVID-19 vaccine cards are largely a thing of the past in 2026, some specific regions in Africa or South America still require proof of Yellow Fever vaccination. Finally, you will need your physical or digital Boarding Pass, which is issued only after your documents have been verified by the airline's security systems. It is always wise to have a digital folder on your phone containing scans of all these documents in case of technical issues.