In 2026, the consensus among travel security experts is yes, you should put a lock on your luggage, but it must be a TSA-approved lock. These locks feature a specific "Red Diamond" logo, which signals to airport security that they can open the bag using a master key for inspection without damaging your suitcase. Using a non-approved lock often results in security agents simply clipping the lock off, leaving your bag unsecured for the remainder of its journey. While a lock won't stop a determined professional thief with a knife, its primary purpose in 2026 is to serve as a deterrent against "crimes of opportunity" by baggage handlers or hotel staff, and to prevent the zippers from accidentally popping open during the rough automated sorting process. Additionally, a locked bag protects your privacy from casual snooping. For added security in 2026, many travelers also use GPS trackers (like AirTags) inside their locked bags. If you are worried about your bag being tampered with, some choose to use heavy-duty zip ties as a disposable "seal," though you must carry a safe way to cut them off (like a nail clipper in your carry-on) once you arrive at your destination.