Every airport publishes a minimum connection time (MCT) — the shortest gap between landing and taking off again that it considers workable for a given pair of flights. Booking below it is one of the most common causes of a missed connection, so it's worth understanding how the number is set and what it actually covers.
What a minimum connection time is
An MCT is not a guess or a rule of thumb — it's a figure set by the airport authority (sometimes with the airline) based on how long it genuinely takes an average passenger and their bags to move between two flights there, given the terminal layout, security setup and how far apart gates typically are. Booking systems use these figures automatically: if you try to book a connection shorter than the published MCT, most airlines and travel agents simply won't sell it to you as a single itinerary.
Domestic vs international connections
If you're routing through a country you're only transiting rather than actually visiting, it's also worth checking whether that transit needs a transit visa — a separate question from the MCT itself, but one that can add significant extra time or paperwork to what would otherwise be a straightforward connection.
The same airport usually has several different MCTs depending on the type of connection:
- Domestic to domestic — typically the shortest, often 30–45 minutes at efficient hub airports, since there's no immigration or customs step.
- International to international — usually 45 minutes to over an hour, and longer again if you have to clear security a second time or move terminals.
- International to domestic, or vice versa — often the longest of all, because it may involve clearing immigration, collecting and re-checking bags, and passing through security again, particularly in the United States.
Large hub airports with multiple terminals connected only by a bus or train — several major US and Asian hubs among them — tend to set noticeably longer MCTs than compact single-terminal airports where everything is a short walk.
What actually eats the time
An MCT has to account for the slowest realistic step in the chain, not the average one: taxiing to the gate after landing, walking or being bussed to the connecting terminal, clearing a second security check if required, immigration and passport control on international-to-domestic connections, and reaching the departure gate before boarding closes. On paper, 45 minutes sounds like plenty; in practice, a delayed taxi-in or a queue at a second security checkpoint can consume most of it before you've even found the gate.
Who's liable if you miss the connection
This depends entirely on how the flights were booked, which is the single biggest factor in whether a missed connection is the airline's problem or yours.
On a single ticket (one booking reference, even across two airlines in an alliance), the airline is responsible for getting you to your final destination if a delay on the first flight causes you to miss the second — they'll typically rebook you on the next available flight, and in many cases provide meals or accommodation if the wait is long. This protection generally only applies to connections booked at or above the airport's own MCT.
On separate tickets booked independently — including through some third-party sites that combine two unrelated bookings — you are on your own. If the first flight is delayed and you miss the second, the airline operating the second flight owes you nothing, because as far as they're concerned you simply didn't show up for a flight you'd booked. This is the core risk of self-transfer itineraries.
How much buffer to add above the minimum
The published MCT is the floor, not a recommendation — it's the shortest connection the airport considers workable under normal conditions, not under a delay. A rough, hedged approach that experienced flyers use:
- Domestic connections at a familiar, single-terminal airport: MCT is often fine.
- International connections, or any connection through a large multi-terminal hub: add an extra 30–60 minutes above the MCT if you have any choice in the booking.
- Connections that involve immigration, a terminal change, or peak-hour security queues: build in as much slack as you reasonably can, especially on the last realistic flight of the day, since a missed connection then can mean an overnight delay.
- The tighter your connection, the more it matters whether you're on a single ticket with rebooking protection or several separate ones.
Checked bags and connections
If your bag is checked through to your final destination on a single ticket, it's the airline's job to transfer it — you don't need to collect it, though on some international-to-domestic routings you may have to clear customs with it before rechecking. On separate tickets, you'll usually have to collect your bag after the first flight and check it in again for the second, which adds a meaningful amount of time and is another reason self-transfer connections need a longer buffer than the bare MCT.
Layovers long enough to leave the airport
At the other extreme, a connection far longer than the MCT — several hours or more — opens up the question of whether you can leave the airport altogether rather than simply waiting it out. This depends on your visa situation and the specific airport; see our guide on leaving the airport during a layover for what's realistic, and our guide to sleeping in airports if your long connection falls overnight instead.
What to do if you're cutting it close
If you land and know the connection is tight, moving quickly matters: head straight for the gate rather than stopping for anything else, and if the airport has a fast-track path for tight connections (increasingly common at major hubs, sometimes signposted or staffed by ground crew who redirect passengers off the aircraft first), take it. If you do miss the connection and you're on a single ticket, go straight to the airline's transfer desk rather than the general check-in queue — they can usually rebook you faster there.
Frequently asked questions
Can I book a connection shorter than the airport's MCT?
Most booking systems won't let you construct a single itinerary below the published MCT. If you're combining two entirely separate bookings yourself, you can end up with a shorter gap than the airport considers safe, which is one of the main risks of self-transfer.
Does the MCT include time for checked baggage transfer?
Yes, for single-ticket connections the published MCT already accounts for the airline transferring your checked bag between flights, so you don't need to add extra time for that specifically.
Is the MCT the same for every airline at a given airport?
Broadly yes, since it's set by the airport authority based on the physical layout, though individual airlines can apply slightly more conservative minimums for their own connections.
What happens if a delay pushes me under the MCT on a through ticket?
If it was the airline's fault (an earlier delay on their own schedule), they're generally responsible for rebooking you, and in many cases for reasonable expenses if the delay is significant — check the specific carrier's conditions of carriage.
Sources and further reading:
- Industry standards on connection times and through-checked baggage: IATA.
- Individual airport minimum connection times are published on each airport's own website.
- Passenger rights on missed connections vary by ticket type and jurisdiction — check the operating airline's conditions of carriage.