Airport check-in

Airport check-in is the process whereby an airline approves airplane passengers to board an airplane for a flight. Airlines typically use service counters found at airports for this process, and the check-in is normally handled by an airline itself or a handling agent working on behalf of an airline. Passengers usually hand over any baggage that they do not wish or are not allowed to carry in the aircraft's cabin and receive a boarding pass before they can proceed to board their aircraft.

Check-in is usually the first procedure for a passenger when arriving at an airport, as airline regulations^{[citation needed]} require passengers to check in by certain times prior to the departure of a flight. This duration spans from 15 minutes to 2 hours depending on the destination and airline (with self check in, this can be expanded to 30 days, if checking in by online processes). During this process, the passenger often has the ability to ask for special accommodations such as seating preferences, inquire about flight or destination information, accumulate frequent flyer program miles, or pay for upgrades. The required time is sometimes written in the reservation, sometimes written somewhere in websites, and sometimes only referred as "passengers should allow sufficient time for check-in".

In-town check-in service is a service offered by some cities such as Abu Dhabi, Seoul, Hong Kong, Delhi, Kuala Lumpur, London, Vienna and Taipei, where passengers may check in luggage in designated places within the city but outside the airport. This reduces check-in time and queuing at the airport.

If passenger is checked in for only one sector of the flight, then it is called destination or point check-in.

If a passenger is checked on all the onward flights and has boarding passes for all the connecting flights and bags are also through checked to the final destination i.e. passenger does not need to recheck themself and the baggage again on the transit, then the check-in is known as through check-in. A passenger can avail through check-in facility mostly when the travel is completely with one single airline.

At the time of check-in, one of the agent's primary duties is to check for valid documents. This includes tickets, passports, visas, letters of consent, and in some cases, passengers' address and contact details to comply with immigration requirements.

Some airlines may ask passengers to present the original credit card used for payment.

At the time of check-in, the passenger hands over baggage which is checked by the airport security and may be sealed (subject to the security regulations in that country). Anything that is above the weight limit or which is not allowed to be carried by the passenger themselves in the aircraft cabin is usually handed over to the agent at the time of check-in. The baggage allowance, if any, is prescribed by the airline and anything in excess may be refused or warrant additional surcharges, at the airline’s discretion.