Quick answer: If you're flying to or through the USA, use a TSA-accepted lock. US security can open it with a master key instead of cutting it off. For other countries it's still the safer choice, because a few other countries' screeners use the same master-key system, and a non-TSA lock will simply be cut if your bag needs a hand search. Choose a combination lock so there's no key to lose, and add a luggage strap for a second layer of security.
Disclosure: Trip Topp sells the lock and strap linked in this guide.
What is a TSA lock?
TSA is the US Transportation Security Administration. A TSA-accepted lock (look for the red diamond Travel Sentry logo or the Safe Skies torch) has a keyhole that a security officer can open with a master key. If your checked bag is chosen for a hand search, they open the lock, inspect the bag and relock it.
What happens with a non-TSA lock?
If US security needs to open a bag with a non-TSA lock, they cut the lock. The bag then travels the rest of the way unlocked, usually with an inspection notice inside.
Do you need a TSA lock if you're not going to the USA?
You don't strictly need one, but it's still a sensible choice. A handful of other countries' screeners use the Travel Sentry master-key system, and in most others security can cut any lock if they need to get in. A TSA lock costs about the same as a standard lock, and it gives you the best chance of your lock arriving intact on a trip that includes a US connection.
Australian domestic flights don't require a lock at all, but one deters casual theft from checked bags.
Combination or key lock?
For travel, a combination lock is almost always better:
- There's no key to lose in a hotel room or at security.
- You can share the code with travel companions.
- You can lock both zip pulls on a suitcase with one lock on each.
Our TSA 3-digit combination lock is TSA-accepted and keyless, and it fits standard suitcase zip pulls.
How to set a combination lock
- Open the lock at the factory setting, usually 0-0-0.
- Press and hold the reset button or lever.
- Turn the dials to your new code.
- Release the reset button.
- Test the code a few times before you lock anything.
Avoid obvious codes like 0-0-0 or 1-2-3, and note the code somewhere safe that isn't in your bag.
Add a luggage strap
A CodeSafe luggage strap wraps around the whole suitcase. If a zip is forced, the strap still holds the bag shut, and a bright strap makes your bag easy to spot on the carousel. The CodeSafe strap has its own built-in combination lock.
TSA vs non-TSA locks compared
| Feature | TSA lock | Non-TSA lock |
|---|---|---|
| US security access | Opened with a master key | Cut off |
| Likely to arrive intact on US trips | Yes | No |
| Best for international trips | Yes | Only if no US connection |
| Fine for domestic Australian flights | Yes | Yes |
Frequently asked questions
Are TSA locks required in Australia?
No. Australia doesn't require locks on checked bags, and the TSA master-key system is designed for US screening.
Can I lock my suitcase when flying to the USA?
Yes, but use a TSA-accepted lock. Otherwise security may cut it off if your bag is selected for inspection.
Do luggage locks actually stop theft?
They deter casual theft and make tampering obvious. A determined thief can still force a zip, which is why a strap adds useful extra protection.
Should I lock my carry-on bag?
It isn't necessary, as it stays with you. For daypacks in crowded places, a bag with lockable zips helps more. See our anti-theft bag comparison.
What else should I know about packing checked bags?
Spare batteries and power banks must go in your carry-on, not your checked bag. Our power bank rules guide explains the 2026 airline changes, and the carry-on allowance guide covers bag sizes.