Booking a multi-city or open-jaw trip

An open-jaw is a single ticket where you fly into one city and out of another, covering the gap yourself. A multi-city itinerary is a single ticket with three or more flown segments in a deliberate sequence. Separate tickets are several independent bookings that you have assembled into a trip in your head but not in any airline's system.

The first two are one contract of carriage, and the airline is responsible for getting you through the whole sequence. The third is not, and no amount of care in scheduling changes that.

Fares are constructed for an itinerary rather than accumulated per flight. A published fare has rules about the direction of travel, the minimum and maximum stay, and whether a stopover is permitted, and a multi-city itinerary is priced against those rules as a whole. This is why adding a third city sometimes costs very little and sometimes costs more than a separate return would.

It also means that an open-jaw is frequently cheaper than you expect. Flying into one city and out of another can price close to a straightforward return, and it removes a backtracking leg from your trip entirely.

A stopover is a deliberate stay of more than a set number of hours at a connecting point, and whether one is allowed — and at what price — is set by the fare rules of the specific ticket. Some airlines actively market stopovers at their hub; on other fares a long layover reprices the whole itinerary.

This is a good thing to ask us about rather than to experiment with in a search box, because the search engine will happily show you a price for something the fare rules do not permit at that price.

Sometimes they genuinely are. A long-haul on one carrier and a regional flight on a low-cost airline that does not interline with anybody can be far cheaper than any single-ticket routing, and if the saving is large and you build in real slack, it can be the right call.

The condition is that you accept the risk explicitly and price it. That means a connection buffer measured in hours rather than the sixty minutes a booking site will let you select, an overnight in the connecting city on the outbound if the schedule is thin, and insurance that covers a missed onward flight caused by a delay rather than a cancellation.

• Check whether your bags are through-checked. On separate tickets they usually are not, which means clearing customs, collecting bags and re-checking in.
• Check whether the connecting airport requires you to pass immigration to move between terminals, and whether you hold the visa or transit permission to do so.
• Put the riskier leg first when you can, so a delay costs you a cheap flight rather than an expensive one.

For anything more complicated than a return, send us the shape of the trip rather than a specific set of flights. We will price the single-ticket construction and the separate-ticket construction, show you both totals with our service fee as its own line, and tell you what each one protects you against. Choosing the cheaper one with your eyes open is a perfectly good decision. Choosing it without knowing is not.