Security checks during a connection: when they're repeated

When a new check becomes necessary

The basic rule foresees a new check when passing from a security area not equivalent to the departure point, a situation common between countries with mutually unrecognized standards. Also, transit between an international flight and a domestic one in the same airport almost always requires an additional check, because the two areas remain physically separate for customs reasons as well as security.

The Schengen exception and one-stop security agreements

Within the Schengen area, intra-EU flights almost always allow transit without repeating the check, thanks to mutual security agreements between the airports. There are also one-stop security agreements between the EU and some non-EU countries with standards deemed equivalent, such as the United States, Canada, and Australia: in these cases the second check can be avoided or simplified, but the list of covered countries changes and should be verified case by case on the airport site.

Liquids and duty free purchases: the risk of a second check

The sealed STEB bag, with receipt visible, protects liquids purchased at duty free only for a limited time: generally up to 3 hours from the moment of purchase. Beyond this threshold, or at an airport that does not apply equivalent agreements, the second security check may not recognize the bag and can seize the purchase, regardless of how much was spent.

If you purchase liquids at duty free before a non-EU connection, check how many hours remain until the second check and, if the connection is not among those with recognized equivalent agreements, postpone the purchase to the last connection before your final destination.