For the carriers which partner with each other on the basis of codeshare or interline agreements, the baggage allowance rules depend on which of the carriers involved in the Most Significant Carrier (MSC). For the identification of MSC, IATA has divided the world into Areas and Subareas. This division is presented below:
|IATA Area||IATA Sub Area|
|North America, Central and South America, Hawaii||USA, Canada, Mexico|
|Europe, Middle East||Europe|
|Asia, Guam, Southwest Pacific||Japan, Korea|
|South Asian Subcontinent|
MSC will be the one which is the first carrier flying between two areas, or, subareas, or, first to cross international borders within a subarea.
But this rule does not apply to flights to/from/through USA or Canada. In this case, the baggage allowance of the marketing airline will be applicable. This is the airline which is listed at first in the ticket.