Check-in counter at a hotel in Hong Kong

Check-in is the process of announcing your arrival at a hotel, airport, sea port or social network service.

Airlines and airports [link]

Check-in at Mumbai International Airport (domestic terminal)

Check-in desks are found in the majority of commercial airports. Their main function is to take in luggage that passengers wish to, or are required to, place within the aircraft's cargo hold and issue boarding passes. After the luggage is weighed and tagged, it is placed on a conveyor that usually feeds into the main baggage handling system. Some airports have curbside check-in, where passengers give their bags to an airline representative right before entering the terminal and then proceed directly to security.

The airline check-in's main function is to accept luggage that is to go in the aircraft's cargo hold. The weight of luggage is limited.

There is an increasing trend towards more automated check-in processes, with many passengers now able to either check-in online before arriving at the airport or use an airline's self-service check-in kiosks at the airport, avoiding queues for the staffed check-in desks.

Hotels [link]

Kempinski Hotel Vier Jahreszeiten check-in

At a hotel, check-in is normally required in order to obtain a room key and provide a credit card guarantee to cover potential costs such as room service for the duration of the stay.

The hotel's check-in time indicates the time from which the hotel starts charging for the day. If anybody wants to occupy the hotel room before the hotel's check-in time, the hotel charges for one additional day and considers it as previous day stay (as compared to occupying the hotel room after the check-in time). Most hotels, however, can accommodate a little buffer time request (typically 30-60 min) by the customers, without any additional charge, if one wishes to take the room before the check-in time. For the most cost-effective usage of hotel room occupancy, the customer should try to reach at about hotel's check-in time and leave or hand over the hotel room at about the hotel's check-out time, but it may not be always practical because the customer's arrival and departure time of flights may not align with the hotel check-in and check-out time and for other reasons.

Social check-in [link]

Many social networking services, such as Foursquare, Google Latitude, Google+, Facebook, Gowalla, GetGlue and Brightkite allow users to "check in" to a physical place and share their location with their friends.^[1]

Users can check in to a specific location by text messaging or by using a mobile application on a smartphone--the application will use the phone’s GPS to find the current location.

Many applications have a “Places” button or tab where a user can see a list of nearby places into which the user can check in. If a location is not on the nearby places list, the user can add the location directly from the phone. Once a user has checked in, they have the option of sharing their location with friends in services such as Twitter or Facebook.

References [link]