If you notice any damage, report it as soon as possible to the carrier, e.g. the airline you flew with.
It is best to report any damage before you leave the airport. If you notice the damage to your luggage only at home or in the hotel, you have, according to the 'Montreal Convention', usually seven days after acceptance of the damaged luggage to claim such so-called "flight damage".
Our tip: It is best to act immediately!
Please note: Damage to luggage caused en route by third parties such as the airline, bus or shipping company is not a case for the legal warranty. Therefore, the damage to the suitcase must be assessed by the party responsible and (if necessary) repaired or replaced.