Short layover: when it's really worth booking a tight connection

The minimum connection time published is not a safe margin

Every airport sets its own minimum connection time (MCT), the threshold below which airlines stop selling that connection. At Frankfurt it rose to 60 minutes for Lufthansa flights as of March 2025, while the standard remains 45 minutes between two Schengen flights. A margin just above this threshold should be treated as a concrete risk, not as a comfortable timeframe.

The risk grows if the first flight arrives from a route with a history of frequent delays: a 20-minute delay at departure can wipe out an already tight margin, while the same delay on a two-hour connection goes unnoticed.

Single ticket or separate bookings changes who takes the risk

With a single booking, even across different airlines in agreement, it's the airline that must rebook you on a later flight if you miss the connection, and in certain cases you also have a right to assistance or rebooking. With separate tickets for the same itinerary, the economic risk remains entirely yours: if the first flight is delayed, the second ticket is treated as a no-show and forfeited.

This difference alone often justifies a single booking even at a slightly higher price when the connection margin is tight.

Terminal, baggage, and airport knowledge make a practical difference

A connection with gates in the same terminal carries different risk than one requiring a terminal change with a shuttle: at airports like Heathrow or Madrid-Barajas the move alone can require 20-30 additional minutes. With separate tickets, the number of bags to retrieve also counts toward the calculation, because each suitcase adds unpredictable time to baggage claim.

Someone who already knows the airport from previous trips can accept a tighter margin than someone passing through for the first time, simply because they already know where the gates are and how long it takes to reach them.

If the margin stays close to the minimum published by the airport, add at least 30-45 minutes of buffer when the first flight arrives from a route with frequent delays, or book an earlier connection on the same route: it costs more only on paper, far less than a missed connection.