The United States Transportation Security Authority does not have a specific lock requirement; passengers can choose to use a lock if they prefer. The TSA does require that luggage be accessible for a security search even if the owner is not present and if a lock is used they will need to cut it open. To assist passengers who wish to use locks, they have designated certain locks, which can be opened with a master key, as TSA-recognized locks.
The TSA worked with lock companies to design a TSA-recognized lock that can be opened with a universal master key. This prevents TSA officers from having to cut the lock and potentially damage the luggage. These locks typically can be purchased at travel stores and airport gift shops and the packaging will indicate that they can be opened by the TSA.
As of 2015, the approved locks use the TSA Lock System that was developed by Travel Sentry. Passengers can identify these locks by its red diamond identifying mark. The locks are designed to be used at airports throughout the world. Each lock has a special code that tells TSA security officers which tool they need to use to open the lock. These locks also allow officers to inspect bags more quickly since they do not need to break the lock. Officers can relock it after the luggage has been inspected.