Leaving from Geneva, I remembered after security that I didn't had any gifts...

Amongst the usual chocolates, I found the perfect gift: a Swiss knife that I proudly bought.

Few minutes later I realized... How is that possible? The blade doesn't exceed the palm of my hand but this is still a brand new sharp knife.

Does that mean that I will be allowed to carry this knife in my hand luggage through this airport security? What about others?

  • 3
    At some point, I remember discussions about putting knives in a package similar to a tin can, that could only be opened with a can opener so as to make it impossible to use the knife before completing your journey. I don't know what became of that…
    – Relaxed
    Commented Aug 10, 2017 at 14:02
  • 6
    It's important to be careful since the knife could be prohibited at other airports. You could fly Zurich-New York and then discover you can't take the knife through TSA security to get it back home. Commented Aug 10, 2017 at 18:21
  • 2
    @ZachLipton Fortunately, when you get to New York, you'll have to claim your checked bags at Customs before going back through security anyway, so you can just shove it in there at that time. That is, assuming your next destination is also in the U.S. If you're connecting international-to-international (e.g. to Canada or Central/South America) from NY, then you don't claim your bags for U.S. customs. In that case, your best bet is to either try to mail it on or just put it in your carry-on and hope TSA doesn't notice (which statistics as well as my personal experience suggest they won't.)
    – reirab
    Commented Aug 10, 2017 at 20:28
  • 37
    Congratulations! You've discovered that most airport security is actually security theater.
    – Mark
    Commented Aug 10, 2017 at 21:30
  • 4
    @MartinSchröder Actually, that makes sense. They know duty free liquids are what they say they are. Commented Aug 11, 2017 at 5:10

3 Answers 3


Knives with blades smaller than 6 cm seem to be mostly allowed in hand luggage. For example, this UK government website and SWISS Hand Baggage guide mention it:

Not to be carried in hand baggage: (...) Knives with blades more than 6 cm long

On the other hand, Forbidden baggage section on TAP site says

For security reasons, certain objects are not allowed in hand baggage. (...) Pointed or sharp objects: objects that due to their sharp tip or cutting edge, can be used to cause serious injury;

So it seems it depends on the airline and the airport.

It happened to me in Switzerland, that I bought a knife in Zurich (in the city center) and before flying out I forgot to put it in my suitcase and took it as a hand luggage. When passing the security I took it out and asked the guard if I should throw it away, he said it's small enough and I can carry it with me.

  • 6
    In Lisbon I had to take my swiss knife off my hand luggage. Luckily, the post office there is about two minutes walk from security check so I just sent it home.
    – Neusser
    Commented Aug 10, 2017 at 13:28
  • @Neusser good to know, I added an excerpt from TAP saying any knives are disallowed when flying with them.
    – Kuba
    Commented Aug 10, 2017 at 13:36
  • 8
    I forget which US airport it was, but TSA found a very small knife in my bag, and they had mailing boxes right there at the station so I could mail it home. The price was higher than standard postage, but it was worth it to save the item.
    – JPhi1618
    Commented Aug 10, 2017 at 18:17
  • 2
    TSA in Ontario Airport (California) would not allow me to pass through with a corkscrew that had a tiny fold-out blade for cutting the wax or wrapping off of bottles. They said it’d be fine if I could break the blade off. I rather wish there had been a postage option as @JPhi1618 suggests: I ended up paying a ridiculous fee to check another bag so that it could arrive intact.
    – KRyan
    Commented Aug 10, 2017 at 19:06

All countries handle this differently. Speaking as a former TSA in USA. It would not be allowed past a checkpoint. If it is discovered via screening you would need to find an a way to transport it NOT with passengers. When you reach US soil, you will need to pass through Customs with your checked bags. Take this opportunity to place the knife in one of them as you will need to be re-screened before boarding.

*The preceding was true 6 years ago. Rules change. Please be aware of current regulations.


This was a hot topic a few years ago when the so-called "journalists" from Daily Mail found out about this possibility http://www.dailymail.co.uk/news/article-2396327/Airport-security-farce-Deadlier-knives-used-9-11-sold-duty-free-taken-London-flight.html Maybe also due to the draconic UK knife laws they saw it as an extremely dangerous thing.

The Daily Mail article claims (not that I trust this tabloid too much):

  • Expert says he would not have been able to board UK flight with the blades
  • On U.S. flights all types of blades, even penknives, are banned

According to Wikipedia:

A common regulation for cabin baggage restrictions was introduced on 6 November 2006 in European Union and in Switzerland, Norway and Iceland: ... The recommendation allows for light knives and scissors with blades up to 6 cm but some countries do not accept these either (e.g. nail care items)

@Kuba referenced the UK website which mentions knifes above 6mm to be forbidden. But I would expect to have problems with a small knife on a UK airport in practice too. At least Daily Mail claims so. Remember that "Airport security staff won’t let anything through that they consider dangerous - even if it’s normally allowed in hand luggage." (https://www.gov.uk/hand-luggage-restrictions)

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .