A lock isn’t strictly required, but a genuinely TSA-recognized one adds a reasonable, low-cost deterrent against opportunistic tampering during handling, without the risk a non-recognized lock carries of being cut off if the bag is selected for inspection.
Some travelers choose to leave checked bags unlocked deliberately, on the reasoning that an unlocked zip is less likely to be forced or damaged during a search than a locked one that needs to be cut. Both approaches are reasonable; the meaningful mistake is using a lock that isn’t genuinely TSA-recognized, which combines the downsides of both — added cost, and a real risk of being destroyed anyway.
For valuables or anything genuinely sensitive, a checked bag generally isn’t the safest place regardless of the lock — carrying high-value items in cabin luggage avoids the question of checked-baggage security entirely.
Check with your airline and read the label before you follow anything here. Lithium battery watt-hour limits, liquids allowances and lock policies differ by carrier and by country, and change over time — the figures published by the airline or security authority you are actually traveling with take precedence over anything written on this site. A power bank or spare battery is carried exactly as its manufacturer and your airline specify, never estimated. We report what is published — a watt-hour rating, a size limit, a lock's official recognition — and this site describes the equipment only: nothing here is a guarantee about what a specific checkpoint will allow on a specific day.
Last reviewed 26 August 2026