Transit and layover rules
What happens during a connection depends on whether you stay airside or pass through customs, which terminal you are in, and which country you are transiting. These factors determine whether your bags are re-screened, whether duty-free liquids survive the connection, and whether you need a transit visa.
Airside transit
Airside transit means remaining within the secure zone of the airport throughout your connection. You do not clear immigration, do not pass through customs, and do not collect your checked baggage. Your bags are transferred between aircraft by the airline.
For most hub-to-hub connections on a single booking, airside transit is the default. Security re-screening at the transit airport may or may not occur depending on the country and airport. At most European and Middle Eastern hubs, passengers transiting between two non-Schengen flights do not go through a secondary security checkpoint.
Airside transit does not mean unrestricted movement within the terminal. You are confined to the secure zone and can only access facilities within it. At large airports, the airside zone is extensive; at smaller airports it may be a single corridor.
Landside transit
Landside transit means leaving the secure zone — clearing immigration, collecting your baggage from the carousel, clearing customs, and then re-checking your baggage and going through security again for the onward flight.
When you re-enter security during a landside transit, you are treated as a new departing passenger. The 100 ml liquids rule applies from that point. Duty-free items purchased before the transit are subject to confiscation if they exceed 100 ml and do not have a valid STEB bag that the checkpoint officer accepts.
Landside transit may also require a transit visa or entry visa depending on your nationality and the transit country. Some nationalities require a visa even for a short landside transit — check requirements well in advance.
When you must clear customs
- Terminal change at airports where terminals are not connected airside (LHR T4–T5, some FRA transfers)
- Overnight connections where no airside facilities are available
- Connections booked on separate tickets where you must collect and re-check bags
- Arriving in the US, Canada, or Australia — all require customs clearance regardless of onward destination
- Some countries require all international arrivals to clear immigration regardless of connection type
- United States: all arriving passengers clear US Customs and Border Protection; bags collected and re-checked even if connecting
- Canada: all passengers entering Canada must clear CBSA; Customs Act applies
- Australia: all arriving passengers complete biosecurity declarations; bags through Australian Border Force
- UK: no automatic customs clearance for airside-to-airside connections; landside entry triggers UK customs rules
- Schengen Area: first port of entry clears customs for Schengen-wide travel
Re-screening and duty-free liquids
When you pass through a security checkpoint during a transit — whether landside or at a connecting terminal — the officer applies that airport's rules. The 100 ml limit is enforced from the point of re-screening forward. Duty-free liquids purchased at an earlier airport may be confiscated if:
- The transit country does not recognise STEB bags (notably the US)
- The STEB bag has been opened or tampered with
- The checkpoint officer determines the receipt is insufficient or mismatch
- The items are above 100 ml and no STEB is present
Buying duty-free at your final departure airport — rather than at transit stops — avoids this problem entirely. See the duty-free and STEB bags page for the full picture.
Hub airport guide
| Airport | Transit zone | Visa requirements | Key notes |
|---|---|---|---|
| SIN — Changi (Singapore) | Airside transit available for most connections; no re-screening for passengers remaining airside; large transit zone with hotels, gardens, and entertainment in transit | Transit visas: not required for most nationalities for airside transit; check for specific nationalities | One of the smoothest transit experiences globally; Terminal 1–4 connected airside; Jewel Changi accessible from T1 airside |
| DXB — Dubai (UAE) | Large airside transit zone across three terminals; extensive duty-free shopping; no re-screening for airside-to-airside connections | Transit visa not required for most nationalities for stays under 96 hours airside | T1 and T3 connected airside; T2 (flydubai) requires separate transfer; confirm terminal when booking |
| DOH — Hamad (Qatar) | Purpose-built transit hub; single large terminal with airside hotel; minimal re-screening for connections | Qatar Transit Visa available on arrival for eligible nationalities; transit without visa for short airside stays in many cases | Generally efficient connections; large duty-free zone in transit |
| HKG — Hong Kong | Airside transit available; passengers remaining airside do not clear immigration or customs | Transit without visa for most nationalities for short airside stays | Same terminal connections straightforward; confirm gate transfers in advance |
| ICN — Incheon (South Korea) | Airside transit; 72-hour Transit Without Visa (TWV) program for eligible nationalities allows landside access to Seoul | TWV program: 34+ nationalities eligible for 72-hour visa-free entry via landside transit | Transit hotel available airside; free city tours offered for longer layovers |
| AMS — Schiphol (Amsterdam) | Single terminal building; Schengen-to-Schengen connections may require security re-screening; non-Schengen-to-non-Schengen transit is airside | Schengen transit visa required for some nationalities even for airside transit | Duty-free confiscation risk for non-EU passengers on Schengen-connecting legs; airport layout can be confusing for transit |
| FRA — Frankfurt (Germany) | Terminal 1 and Terminal 2 connections require transit between buildings; airside connections possible within same terminal area | Schengen area; transit visa requirements apply for some nationalities | Terminal change involves bus transfer and potential re-screening; allow extra connection time; Lufthansa hub |
| LHR — Heathrow (London) | T2 and T3 share an airside corridor; T4 and T5 are remote and require landside transfer for connections between them and T2/T3 | UK Transit Visa required for some nationalities; UK is not Schengen | T4–T5 and T2/T3–T5 connections require departing secure zone, bus transfer, and re-screening; plan 90+ minutes for these connections |
Transit policies change. Verify current visa requirements with the relevant embassy and confirm terminal connections with your airline before travel.
Self-connecting
A self-connection occurs when you book two or more separate tickets for a journey rather than a single through-booking. Airlines have no obligation to accommodate you if the first flight is delayed and you miss the second. You are responsible for collecting and re-checking your bags between flights even if the airlines are the same.
Self-connections always trigger landside transit at the midpoint — you must collect your bags, clear customs, and re-check in with your next airline. The 100 ml liquids rule applies at re-screening. Any duty-free items in your carry-on from the first leg may be subject to confiscation at the security checkpoint for the second leg.
Allow significantly more time for self-connections than for connections on a single booking. Minimum practical self-connection times at most major airports are 2.5 to 3 hours, and more at large airports with terminal transfers.