Two concepts for baggage weight limits are in use.
Piece Concept The Piece Concept applied only to passengers traveling to or from the Americas. From 1 August 2019, however, Vietnam Airlines (IATA Area 3) adopted the Piece Concept. Under the Piece Concept, passengers are permitted to check in a certain number of suitcases with a per-bag weight of up to 23 kilograms for Economy Class, and up to 32 kilograms for Business or First Class. The allowed weight per suitcase and the number of suitcases varies per airline and depends on the class, elite status, type of ticket, flight origin, and destination.
Weight Concept Under the Weight Concept, each passenger can check in a total weight regardless of the number of suitcases. Often passengers traveling together can also combine their allowed weights. The total weight varies per airline and depends on the class, elite status, type of ticket, flight origin, and destination.
Baggage pooling During the departure in an
airport, assembling all the associated baggage of passengers who are to be checked in together and
checking those baggages in the name of one passenger is known as a pooling of the baggage. ==Fees==