The check-in process at airports enables passengers to confirm they will be on the correct flight, obtain a boarding pass, possibly select their seat (if hasn't happened already and is allowed by airline), and check in luggage onto a plane, if desired.

Checking in for an international flight in 2026 involves a rigorous verification process that extends beyond simple seat selection. Unlike domestic flights, the airline must confirm that you possess a valid passport and any necessary visas or entry permits (like an ESTA or ETIAS) for your destination. If you check in via a mobile app, you will often be prompted to scan your passport's chip or upload a photo of your travel documents. At the airport, if you have checked baggage, your bags will be weighed and tagged to your final destination; for international routes, the standard allowance is often 23 kg (50 lbs) for economy. You will receive a boarding pass—either digital or paper—and then proceed through security and immigration control, where your identity is cross-referenced with government databases. In 2026, many major hubs have replaced traditional document checks with biometric gates that use facial recognition to match you to your passport data, significantly speeding up the "boarding without a boarding pass" experience.