For example, sometimes airport security allows passengers to keep their water bottle even though it's over 100mL or keep their shoes on, while sometimes they do not. I would like to know the rules before going to the airport.

Examples of motivations: some liquids can be expensive, I may become hungry if they throw away my food that the security classifies as liquid, and I may pack differently if I must extract my laptop from my backpack.

  • 1
    Look at the airport website?
    – Xnero
    Commented Jan 1, 2023 at 21:09
  • 2
    In some cases it depends on which part of the airport. I remember that Schiphol (Amsterdam airport AMS) had one set of rules for the within Schengen area and one for the international area at one time, to be changed slowly to one set of rules later when they had time to change over all machines.
    – Willeke
    Commented Jan 1, 2023 at 21:10
  • @Xnero thanks, may be tough or impossible to find there for some. I'd prefer a resource that allows me to input the airport code and perhaps some other information, and outputs the security rules. Commented Jan 1, 2023 at 21:11
  • 1
    In the US the rules may also be different depending on whether you have TSA PreCheck or not. In some places some rules depend on whether you go through mm scanners or regular scanners (either but choice or by luck, depending on availability).
    – jcaron
    Commented Jan 1, 2023 at 21:57
  • 3
    @Xnero most airport websites are mostly useless. You can't even find important info like "do I have to go through security for my connection?" or "can I transfer airside from Terminal X to Terminal Y".
    – Hilmar
    Commented Jan 2, 2023 at 16:32

1 Answer 1


You can't.

It's frustrating and annoying but specific rules for security are not published and seems to change from time to time. It could be that publishing exact procedure would make it easier for perpetrators to work around the process. More likely, it's just extra effort than no one wants to do. TSA fails it's internal tests in 90%+ of all cases, so it's more theater than actual security.

  • 2
    TSA even has a name for the lack of some published rules: Unpredictable Screening Procedures. Sometimes I've even seen them take an extra measure and then remove a different measure as a result (e.g "because a dog sniffed here, everyone in this line doesn't have to take off their shoes"). Some checks may be random, and other niceties like making an exception instead of throwing away your liquid may be up to individual discretion. There's no real way to know. Commented Jan 3, 2023 at 1:27
  • @ZachLipton I once witnessed in the USA, the TSA checking the drinks of passengers boarding a flight - when those drinks (large cups of coffee) could only have been bought after the TSA security checkpoint.
    – Peter M
    Commented Jan 3, 2023 at 16:02
  • @PeterM Why were the TSA away from their posts? I've never seen anything like that. Commented Jan 3, 2023 at 21:24
  • @AzorAhai-him- I have no idea. It was strange at the very least.
    – Peter M
    Commented Jan 3, 2023 at 21:52
  • TSA is hit or miss. They do a lot of things they shouldn't be doing and they don't do a lot of things they should be doing
    – Hilmar
    Commented Jan 4, 2023 at 21:36

You must log in to answer this question.

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