What kind of luggage locks?

Small nylon cable tie. If used on the way out, you might pack a nail clipper in the outside pocket to make sure you can get into the bag if you need to.

If they choose to open the bag, as they have the right to, you want to have no damage to the bag. Pay attention to check-in deadlines in London. They are related not only to the airline's convenience, but to U.S. requirements for passenger roster submission.

Actually I've never locked my checked bags either going or coming, but then I don't put anything supremely important in them either, just clothes. I put all my important things in my carry-on. I've never had anything go missing out of a checked bag.

You don't have to worry about that "customs gal" at Dulles. If that is your port of entry into the U.S., that's where you'll have to retrieve your bag and go through customs and immigration.If it's locked, they ask you to open it.

Of course, you may have to worry about the "TSA gal" once you recheck your luggage for your flight to your home airport. But if it's a TSA lock, she will have a key.

If you use a TSA approved lock, most security agents will be able to access it. If not and they want to, they will cut the lock.

As advised above, don't pack anything too valuable in your checked luggage. I follow that advice and still lock my bags. It isn't foolproof, but makes it a little harder for a potential thief to just do a quick unzip and grab, even if I did pack something they might want.

I always lock my checked bag and a TSA lock is the type that I happen to have now. Heathrow has had a reputation for thefts from luggage in the past. British agents might have the right to open your bag, but it's not my understanding that any European agents commonly do open bags. They just x-ray them, the old-fashioned way. When checking in bags at a European airport, there is no warning sign about your bag being opened.

Ann,

A TSA Lock should be fine, as it's not likely that they'll even access your luggage. I always prefer to lock my Backpack, as the zippers seem to have a way of "opening" due to motion or whatever. A small Padlock is also some deterrent to "opportunistic theft".

It's always prudent to keep valuables with you in the carry-on bag, so there shouldn't be anything of value in your checked luggage anyway.

I locked my bag on a trip to Tallinn last year and when I arrived at my hotel and went to open my suitcase I realized that not only was the entire lock gone (typical small TSA lock) but the zipper mechanism was, too, and the bag was a total loss, had to scramble around and buy a new (expensive!) suitcase to come home. I believe the lock got caught in something that caused it to be torn off, I don't think it was cut off because that wouldn't have damaged the mechanism and surrounding zip channel. After that, no more locking. Nothing irreplaceable goes in my checked bag so I'm not concerned about that. I do bring locks to use on trains or if leaving my bags at the front desk. A twist tie works fine to ensure the bag doesn't open accidentally.

While I generally use TSA locks, probably a few hundred thousand folks keys to open. Really small nylon cable ties in an unusual color have been my go to of late. Very cheap. Found at agricultural supply store. Keep a nail clipper to nip at destination. Cable ties will not stop but would confirm improper access by unauthorized persons...a modest deterrent..

I just use twist ties.

It only took nine hours to convince Ann to stick with the carry-on option...

A TSA lock means nothing to European security. If they want in, they will cut them off. I just use nylon wire ties (cable ties, zip ties). I have had my bag inspected, and they just clip off my wire tie and replace it with a new one.

I used to lock a checked bag, but after damage to the bag, I stopped locking, just used a tie to keep the bag from spontaneously bursting open.

Now I carry on only, and if I have to gate-check the bag (happened one time), I don't worry about anything going missing from it - it never gets to a carousel/clearing area. And, like many posters who do check bags, I don't put anything in it that I can't replace or live without temporarily.

I have yet to experience a flight where I still had locks on my luggage when I arrived at a destination (domestic OR international). Three times I've bought tsa approved locks. Three times I've gotten luggage back without locks- although one time there was one lock dangling, but not closed. So for my next trip in the spring, it's a carry on only- no locks.

LOL Bill in San Diego - Yes, many reasons to only carry-on luggage! Obviously not a black-and-white answer here. But it's very helpful to hear all the options from everyone. I will either put an adequate but not TSA lock on (those are more expensive) that the folks at Heathrow can cut through if they need to, or the zip tie. Thanks! Ann.

I just flew LAX to Heathrow to Zurich, and then CDG to O'Hare to LAX. Wife and I both had TSA locks on our bags on all legs and ..... they were still there at the end of the trip.

I hesitated about using them in Europe but cmon, those "special" TSA keys are probably selling on eBay for $2. I figured all the Euro security folks who cared, already had them.

What I found odd was my connection in Terminal 2 at Heathrow. I stepped off my plane, walked directly towards my connection gate (endless) and ... had to go through security again! Since I was already fully vetted in the States, they should have just had a controlled corridor leading from my one flight to the other. No need to X Ray me and my bags again.

After twice having TSA cut my supposedly TSA-approved locks off, both times in the USA, I no longer lock checked luggage. We normally just do carry on, but after giving up any hope of meeting weight requirements this October on our flight to Germany, we checked our usual carry-ons unlocked. But I took the locks with us for use on the train and for Viking cruise when it felt weird to be leaving unlocked luggage outside in the hotel hallway early in the morning. I bought a big wad of neon orange tags that can be easily cut off, just to tell me if TSA had been in the luggage, but I've never actually used them on suitcases. They work great on eBay to keep scammers from returning their old items to me.

Oh, and one unexpected benefit of checking bags on our flight from LAX to Dusseldorf and then on to Munich was that Air Berlin checked the bags straight through to Munich so we didn't have to keep track of them for 3 hours between flights.

I don't use locks but prefer the steel cable key chain wires. They are reusable and I put them on my luggage and backpack just so I am not the lowest hanging fruit. You simply twist them (a little locking socket on the end goes into a little threaded piece) to get them off, but it takes a few minutes so a pickpocket wouldn't be likely to target your backpack. They are reusable so you don't carry a bunch of them. Airlines can get the wires off and on if they take a minute or two to figure them out, but if they cut them, the cost is only about 10 cents each.