Abstract: A baggage checking system is described, primarily for use at airports and distinct from airline seat reservation systems. The baggage checking system takes flight numbers, travellers' identification data and baggage tag numbers from check-in and transfer desks and collates it with baggage tag numbers read at baggage loading points. If an attempt is made to load a bag on an incorrect flight an alarm is given at the loading point and the system is inhibited at that loading point until supervisory action is taken. In addition an alarm is given if an attempt is made to load a bag with the same tag number as another bag. Rules concerning when an alarm should be given in relation to tag numbers checked-in, and tag numbers of passengers boarded can be changed at will, even during loading.