There are three kinds:

• Destination open jaw. Fly out to one city and home from another.

• Origin open jaw. Fly home to a different airport from the one you left.

• Double open jaw. Both.

Open jaws suit touring holidays and twin-centre trips. In a GDS, the part of the journey that is not flown is shown as a surface sector, usually marked ARNK, for arrival unknown.

Example: London to Venice on the way out and Rome to London on the way home, with the journey from Venice to Rome by train.

Pricing

With airlines that price return journeys as a whole, an open jaw is normally priced from half return fares, subject to the fare’s rules on combining fares. These can limit the surface sector, for example to no longer than the longest flown part of the journey, or to within one country or region. Some fares do not allow open jaws at all, so check the fare rules before you quote. With airlines that sell each direction as a one-way fare, which includes most low-cost airlines, an open jaw is simply two one-way fares, whether booked together or separately.

Worth knowing

An open jaw is not the same as a stopover, or a multi-city itinerary in which every leg is flown, although consumer booking sites often call it multi-city. A touring package with open jaw flights is still a flight-inclusive package that needs ATOL cover.