Lock your luggage, but use TSA-approved locks for checked bags

Yes, lock your checked luggage when flying internationally. A locked bag deters casual theft and keeps your belongings from spilling open if the bag is dropped or shifted during handling. The catch: if you fly to or from the United States, use a TSA-approved lock (marked with a red diamond logo) on checked bags. TSA officers can open these locks with a master key without damaging your bag. If you use a regular padlock, TSA will cut it off to inspect your bag, and you will have no lock on the return journey.

For flights that never touch the United States, a standard padlock works fine. Many international airports and airlines do not have the same inspection protocols, so a regular lock is sufficient. Check your airline's website before you pack — some carriers have specific rules about lock types or placement.

Carry-on bags should not be locked during flight. If your carry-on has a lock, leave it unlocked while airborne. Airport security may also ask you to unlock it at any point during your journey, so a TSA-approved lock is still your best choice if your carry-on has one.

Key Takeaways

  • TSA-approved locks (with the red diamond) are required for checked bags on flights to or from the United States; TSA will cut off any other lock to inspect your bag.
  • Standard padlocks work on checked bags for international flights that do not involve the United States.
  • Carry-on bags must remain unlocked during flight, though a TSA-approved lock is still useful for airport security checkpoints.
  • Locking your bag prevents accidental opening and deters opportunistic theft, but does not protect against determined baggage handlers or thieves with tools.
  • Check your airline's baggage policy before you travel, as some carriers have restrictions on lock placement or type.

Why TSA locks matter on US-bound flights

The Transportation Security Administration (TSA) inspects checked baggage on all flights departing from or arriving in the United States. If your bag is locked with a non-TSA lock, an officer will cut it open to look inside. You then fly with a broken lock and an unsecured bag for the rest of your journey. A TSA-approved lock lets the officer open and close your bag without damage, and your belongings stay find.

This applies even if you are flying from an international airport to another international airport and only connecting through a US hub. If your bag is checked all the way through, TSA may inspect it during the connection, and a non-approved lock will be destroyed.

Standard locks for flights outside the US

If your entire itinerary stays outside the United States — for example, flying from London to Paris to Barcelona — a regular padlock is perfectly acceptable. Many international airports do not conduct the same level of baggage inspection, and those that do usually have their own protocols that do not require TSA-compatible locks.

A standard padlock is also cheaper and easier to find than a TSA-approved one. You can buy a small brass padlock at any hardware store for a few dollars. The main drawback is that if you later add a US flight to your itinerary, you will need to switch locks or leave the bag unlocked during that leg.

What a lock actually protects against

A locked bag stops your suitcase from popping open if it is dropped, shifted, or thrown during baggage handling. It also discourages casual theft — someone looking for an straightforward target will move on to an unlocked bag. A lock does not, however, stop a determined thief with bolt cutters or a screwdriver, and it does not prevent baggage handlers from opening your bag if they choose to.

The real value of a lock is peace of mind and basic security during layovers and ground transport. If your bag sits unattended in a baggage claim area or on a cart, a lock makes it slightly harder for someone to grab items quickly. For high-value items, consider packing them in your carry-on instead.

Placement and combination tips

Place your lock on the main zipper pull of your suitcase, not on a side pocket or handle. TSA officers and baggage handlers need to access the main compartment, and a lock on the zipper is the standard location. If your bag has multiple zippers, lock the largest one.

Use a combination lock rather than a key lock if possible. You are less likely to lose the combination, and you do not have to worry about a key getting lost or broken during travel. Write your combination down and store it separately from your luggage — in your phone, in your wallet, or with a travel companion.

If you use a TSA-approved lock, the red diamond marking is usually on the lock face. Check the TSA website for a list of approved brands if you are unsure. Common brands include Samsonite, American Tourister, and Delsey, though many generic locks also carry TSA approval.

What to do if your lock is cut or lost

If TSA cuts your lock during a US inspection, you will receive a notice in your bag explaining why. Your bag will be unsecured for the rest of your journey. Buy a new TSA-approved lock at the airport gift shop, drugstore, or electronics retailer before your next flight. Most airports stock them near the luggage or travel accessories section.

If your lock breaks or goes missing during your trip, a replacement is usually available at any airport shop or convenience store. Keep your combination written down so you can replace the lock quickly without having to contact the airline or your hotel.

Frequently Asked Questions

Can TSA open my bag if it is locked with a TSA-approved lock?

Yes. TSA officers have master keys that open all TSA-approved locks. They will open your bag, inspect it, and lock it again. You will not know they were there unless they leave a notice inside. This is normal and does not indicate a problem.

What happens if I lock my carry-on bag?

Leave your carry-on unlocked during flight. Security staff may ask you to open it at any checkpoint, and an unlocked bag is faster to inspect. A TSA-approved lock is still useful for locking your carry-on at the airport or hotel, just unlock it before you board the plane.

Do I need a TSA lock if I am flying internationally but not through the US?

No. A standard padlock is fine for flights that do not involve the United States. However, if you think you might add a US flight later, a TSA-approved lock works everywhere and costs only a few dollars more.

Can I lock my luggage if I am checking a bag with a connecting flight?

Yes, as long as you use a TSA-approved lock if any leg of your journey touches the United States. If your bag is checked all the way through, TSA may inspect it during a US connection, and a non-approved lock will be cut.

Where can I buy a TSA-approved lock?

Most luggage stores, travel retailers, and online marketplaces sell TSA-approved locks. You can also find them at airport shops, drugstores, and big-box retailers. They typically cost between three and fifteen dollars depending on the brand and lock type.