While it is not a legal requirement, it is a strongly recommended peer-to-peer best practice to lock your checked luggage in 2026. Locking your bag serves as a deterrent against opportunistic theft by baggage handlers or other transit staff and prevents your bag from accidentally bursting open during the rigors of automated sorting systems. However, you must use a TSA-recognized lock (often identified by a red diamond logo). These locks can be opened by security officers using a universal master key if they need to inspect the contents of your bag. If you use a non-TSA lock, security personnel are authorized to "forcibly remove" it—often by cutting the lock or the zipper pulls—if your bag triggers a manual search. Furthermore, in the era of high-tech travel, many suitcases now come with integrated biometric or digital locks that are also TSA-compliant. While a lock won't stop a determined professional, it provides peace of mind and ensures that your belongings remain contained and private throughout their journey through the airport's underbelly.