A TSA lock is a special form of lock used to secure luggage. These locks were developed in the wake of the tightening of security measures in international travel (mainly in and out of the US). The TSA lock can be opened with a master key from the US Transportation Security Administration.
If suspicious or unidentifiable material is found in a piece of baggage as a result of the X-ray examination, the TSA lock can be opened with a master key, the baggage item can be searched and the lock subsequently closed again. The correct numerical code or key is therefore not necessary for opening the regular luggage lock on luggage equipped with TSA locks.
If a suitcase does not have a TSA lock and, for example, has only a simple combination lock, it may happen that, in the event of a necessary search of the item of luggage, this lock is broken open by the security authorities without asking the owner.
In the meantime authorities of other countries have begun to recognize TSA locks.