InterAirline Through Check-In (IATCI) Implementation Group is an industry interest group including airlines, system/software providers and handling agents/operators involved in development, implementation and usage of interairline through check-in functionality. Currently, it has more than 60 members.

The Group closely co-operates with the International Air Transport Association (IATA) and its Passenger and Airport Data Interchange Standards (PADIS) organisation by providing guidelines for the ATA/IATA EDIFACT Message Standards Document regarding InterAirline Through Check-In (Scenario 1) messages as well as InterAirline Local Check-In and Flight Management (Scenario 2) messages.
IATCI maintains and distributes the IATCI Group Message Implementation Guide document.

The Group also facilitates multilateral agreements and assists in bilateral agreements in connection with the interairline through check-in by maintaining a standard set of documented rules and recommendations. Procedural issues in direct relation to interairline through check-in may be addressed in the meetings as well.

A minimum of one regular meeting per 18 months is foreseen. Meetings are hosted by one of the members varying among the three IATA Traffic Areas. The membership in the Group may be regular, associate or observable. Between the meetings, the members provide the assistance in running Documentation, Administration and Research centres. They are also active in different IATCI ad-hoc activities.

The meetings and other activities are co-ordinated by the Group's chairperson and/or vice-chairperson who are elected for a two year period.