If you don't check in, you won't receive a boarding pass that allows you to board the plane, and your seat might be given up to a standby passenger. The check-in process also confirms your traveler details like your passport information and frequent flyer number.

If you do not check in before the official deadline for an international flight (typically 60 to 90 minutes before departure in 2026), the airline has the right to cancel your reservation and deny you boarding. Unlike domestic flights where there is sometimes a "flat-tire" grace period, international flights require manual document verification (passports and visas) before a boarding pass is finalized. Once the check-in window closes, the airline's manifest is sent to government authorities, and the weight-and-balance calculations for the aircraft are completed; reopening the system for a late passenger can cause a "domino effect" of delays. Even if you checked in online but failed to "Bag Drop" by the cutoff, your luggage will not be accepted. In most cases, you will be considered a "No-Show," and depending on your ticket type, you may lose the entire value of your fare or be required to pay a hefty "rebooking fee" to catch the next available flight.