Montreal Convention baggage rules come from the 1999 treaty (MC99) that sets airline liability caps for delayed, damaged, and lost checked and cabin baggage on international itineraries.
Liability is expressed in Special Drawing Rights (SDR) per passenger, not per bag, and it applies to the operating carrier on the international sector. Support teams handle the claim in three stages: file a Property Irregularity Report at the airport, submit an itemised claim with receipts within the treaty’s window (commonly 21 days for delay, 7 for damage, though verify against the primary IATA or carrier source at build time), and track the payout.
Domestic itineraries fall under national law, not MC99, so the cap and the paperwork differ.
Common questions
Is Montreal Convention baggage liability per bag or per passenger?
Per passenger. Even if a passenger checks three bags and all three are damaged, the total payout for that passenger is capped at the SDR limit.
Who pays under Montreal Convention baggage rules on a codeshare?
The operating (actual) carrier on the sector where the damage or loss occurred. Support agents route the claim to that carrier, not the marketing airline.