Let's say I have an interline booking from a site like Expedia, with the first flight on one airline and the next two flights on another, and I miss the first flight on the itinerary. What happens then? What should I do?

Welcome to Flyer Talk.

If you miss any segment of a multi-segment trip, the remaining segments will be cancelled.

I'm going to guess that you are looking at some kind of Hidden City ticket. That is where a flight through a connection point is cheaper than a flight originating in the connection point.

The typical scenario is that you want to fly HubAirport to Destination. You find that if you fly OtherOrigin-Hub-Destination, the ticket is cheaper. So, rather than traveling to some OtherOrigin and flying back to the Hub, you want to just start in the Hub.

Sorry, but that won't work. Search for "Hidden Cities" in this message board, and you will find huge numbers of messages on this subject.

I'll boil it down for you:

1. Hidden City pricing exists, and the airlines are well aware of that. Higher priced tickets from a hub served mainly by that airline is a large factor in their profit.
2. Attempts on the part of the passenger to skirt Hidden City restrictions are a violation of the Contract of Carriage.
3. You can get away with it if the skipped segment is the LAST segment of your trip (not the first) and you do not check baggage.
4. Finally, don't make a habit of it, such as using Hidden City to commute to a job. The airlines employ data miners who look for these kinds of patterns. Once a repetitive Hidden City violator is identified, that person could receive a scary letter on law firm stationery with the words "fraud", "settlement", "lawsuit", "forfiture" and other similar words in the text.

I am a database administrator, but not associated with an airline. I do similar kinds of data mining all the time. It's not rocket science.

go get a refund on your ticket. you will get full value, less some fee.

take action quickly unless the ticket is fully refundable....you can lose the entire value on some tickets if you don't cancel before the departure of the 1st flight!.....of course, your travel insurance might cover it...

good luck...

Not quite accurate, and indeed quite inaccurate when it comes to interline itineraries.

A lot will depend on whether the plating carrier is the carrier on which you no show. If so, there is a strong chance that your itinerary will be cancelled as stated above.

If your no-show however is on a receiving carrier, what exactly will happen depends upon the level of connectivity between the IET partners and what kind of DCS parameters are in use at the departure airport. Without going into too much of technical detail, most no-shows in this case would be queued for manual review prior to cancelling downline segments - often giving you enough time to actually utilise the subsequent ticket coupons. Even if manually reviewed, if the fare components are not linked (constructed as "end-on-end" rather than "add-on") then your downline segments may not be cancelled at all.

Sound advice though is to not take the chance unless you are 100% sure of what you are doing.

You also note that you purchased through Exepedia. Third party vendors have their own systems and rules. It may well be that if you miss downline segments and they are cancelled that the segments are cancelled, can't be refunded and haeve $0 value. Sounds to me as though what you are seeking to do is exactly what carriers spend a lot of money trying to prevent. If they do catch you, they will exact everything they can from you. This is something you need to take care of today. If this happens to you on departure, your choice will be to buy a new ticket at the walk-up fare (typically a whole lot more than what Expedia charged) if it is even available or to watch the aircraft push back from the gate while standing at the gate.

Welcome to FT!

The airline will probably cancel the remainder of the trip until they hear a response from you.. probably a fee would need to be paid if you missed the first leg, and wish to rebook.