Airlines often price tickets from one city to another through a hub cheaper than flights that terminate at the hub. That’s because there may be more competition between the two cities that are cheaper. And this presents an opportunity called “hidden city ticketing” — you buy the flight to the cheaper destination, connecting where you really want to go, and just get off the plane at your ‘true’ arrival point. (Throwing away the final segment, throwaway ticketing.)

For those who think I’m somehow breaking secret ground here, the post was actually inspired by a recent useful thread on Milepoint and even further I’d note that Nate Silver wrote this up in some detail in the New York Times back in May.

Here’s Silver’s explanation:

Passengers flying to or from airports that are dominated by a single carrier — like Memphis, Newark or Dallas/Fort Worth — pay fares 20 or 30 percent higher than at non-hub airports. The prices are even more inflated when you’re flying from a smaller city with a limited number of flights. A nonstop one-way ticket from Des Moines to Dallas/Fort Worth is $375 on American Airlines, for example — more than the $335 Delta will charge you to fly from Miami to Anchorage.

But what happens when you’re interested in flying American from Des Moines to Los Angeles, which hosts a more competitive airport? That flight is only about half the price ($186), despite its being more than double the distance. Now, here’s the trick: American flights from Des Moines to L.A. have a layover in Dallas. If you want to travel to Dallas, the best way to get a reasonable fare is to book the flight to Los Angeles instead, and simply get off the plane at Dallas.

An airline doesn’t see themselves as selling you a ticket from A to B to C, with you buying flights A to B and B to C. Instead, they see themselves as selling a ticket between A and C, and you happen to stop in B. A ticket from A to B is a totally different product.

Makes sense to people that they’ve bought two flights, they only take one, what’s the big deal since the airline got paid for both? Airlines see you obtaining a different – and likely more expensive – product than the one you paid for.

But it certainly isn’t illegal to buy a ticket and not fly all of the segments (although Silver recommends not actually lying about what you’re doing if caught since that could technically introduce a fraud element).

The practice violates the contract of carriage of most airlines (not Southwest, and up until a few years ago tossing the return portion of a trip and flying only one way wasn’t a violation of United’s but that’s been updated). And a travel agent who consistently sells tickets where final segments are unflown can get a debit memo and owe money, which they need to pay in order to continue selling tickets on the airline (and indeed not to jeopardize their access to the computer reservation system itself). But that’s a contractual and ongoing business issue between airline, reservation system, and agent..

The most that can happen to a passenger is likely that they could theoretically be banned from an airline. Most people don’t care because they aren’t loyal to an airline to begin with. The customer more likely could see consequences to their mileage account. This is something that could happen through repeated and frequent use of the technique, including your mileage number in the reservation. If you consistently buy one-way tickets through Chicago to Milwaukee and get off in Chicago (Milwaukee is often a much cheaper market), and give your United Mileage Plus number each time you do it, United might have a problem with you. United might send you a warning letter. They might threaten your miles. They could even close your account.

On the other hand, they’ll have a more difficult time penalizing your miles if you credit to partner airline programs. It will even be harder, though not impossible, to track. I don’t advise doing this every week. But I’ve never personally known anyone that’s done it only a few times a year per airline to have problems.

Here are some examples of how it works:

• Flying New York to Denver, the price is $600 roundtrip for non-stop flights. You might be able to connect less expensively, but you want the non-stop. So you book Newark- Denver – Hayden, Colorado and get off the plane in Denver. That ticket might be $150 one-way.

  Then for the return you fly Denver to Newark and connect down to Jacksonville, Florida or Atlanta or maybe Orlando. You get off the plane in Newark. That ticket might be $150 one-way.

  You’ve now spent $270 for your roundtrip instead of $600 and still fly non-stops. Instead of crediting the miles to Continental, if you’re finding yourself doing this frequently, you credit the miles to US Airways.

• Last minute tickets up to New York from DC are pricing expensively. A same-day roundtrip runs you $700! So instead you book Washington National to JFK on Delta and connect up to Boston. That one way runs $200. Get off the plane at JFK.

  Then for the return you book the US Airways Shuttle. But the one-way ticket on the Shuttle is running $400. So you book New York LaGuardia to Washington National and on down to Orlando. Get off at National and spend only $180.

  You’re out of picket $380 instead of $700, and still get non-stops to and from New York. You’ve flown into JFK instead of LaGuardia, but you’ll live…

Here’s how I would go about finding these routes. I search one-way using either the ITA Software Matrix or Hipmunk. I specifying my real starting city, and then I let the system find fares to a variety of cities that I know to be generally cheap, and might connect through the city I actually want to go to. And I tell the website to search for other airports within 300 miles of the one I’ve specified too, why not?

And I limit the search by specifying my connecting point as the city I want to go to.

Cheap cities might be Providence, Atlanta (as a connection, not on Delta), Orlando, Jacksonville (Florida), the various cities in Colorado that aren’t Denver, Phoenix, Tucson, Milwaukee, etc. Depending on whet’s in the same general region of the country as where you’re actually going (and sometimes connecting through the Northeast to Florida works great, actually).

So a search could look like:

• From Denver
  
• Connecting at Washington Dulles
  
• To Atlanta, Jacksonville, Orlando, Providence, Charlotte, New York LGA, Pittsburgh (and everything within 300 miles)

That might spit out a cheapest one-way ticket Denver – Washington Dulles – Atlanta. And you get off at Dulles.

There are several words of caution, things you cannot do or risks to be aware of:

• Do this only as the last segment of a reservation. So only throw away the final leg of a roundtrip. Or book two one-ways if you want to do a throw away in each direction. Because when you miss a flight, the airline is likely to cancel the rest of your itinerary.

• Don’t’ check luggage. Most airlines used to let you ‘short check’ baggage, or check it to an intermediate stop and not your final destination. This isn’t usually allowed any longer. United certainly stopped permitted the practice a couple of years ago. If you check bags, your bags will go to the final city in your ticket, you will not. So this only works with carry ons (except for international flights arriving in the U.S. and a few other countries, because you have to pick up your bags on arrival in the U.S. and walk them through customs, then drop them back off. If you’re checked to a domestic destination other than the one you arrive at in the U.S., you can just not drop your bags back off. So if your final destination is your arrival city, you can terminate there. There’s only one exception that I can think of where connecting passengers pick up baggage in a different place from terminating passengers and are expected to re-check and then go through security. But that’s exceptionally rare.)

• Don’t let yourself gate check luggage. For the same reason you don’t want to check a bag, you don’t want to board the plane and find no overhead space and a flight attendant telling you they’ll check your bag to your final destination. That’s not okay, since you aren’t going to your final destination. This works best if you have status or an upgrade, or at least can board in the middle of the pack and not be the last to board. But if you are last to board, there’s no overhead space, and they won’t let you hunt and peck for space, then you need an excuse why you either need to get the carryon on the plane or you need them only to check it to your intermediate destination. In the former case, tell them you’re connecting on a separate ticket to a carrier they’ve never heard of. In the latter, just tell them your final destination is where the aircraft is landing. And they’re more likely to check it to your planned arrival city rather than your reservation’s final destination.

• There’s still a risk of irregular operations. If your flight cancels, the airline might offer to send you to your ‘final destination’ via some other route. That obviously won’t work for you. I’d suggest saying that the connecting city is important, you’re meeting folks in the airline’s club lounge there. Add some color, maybe you’re having an affair there (and only need a 45 minute connection in one fo the conference rooms?). Agents are usually pretty accommodating during irregular operations and will give you an itinerary that works for you if anything is available that suits you. But you’ll need to be proactive about the rebooking.

So how can our example of flying Denver – Washington Dulles – Atlanta go wrong?

United’s Denver – DC flight is delayed. They won’t let you checkin online because the delay means you no longer have a legal connection in DC. They want to re-route you. They’re happy to put you on the non-stop to Atlanta!

You: Umm, I really need to keep the same routing, I am meeting someone and delivering papers in DC. Can’t you get me on a later Denver – DC flight?

Agent: We could but there’s no way to get you to Atlanta then until the next day. I can’t give you that because you’ll have to spend the night, and we can’t pay for the hotel when the delay is due to weather.

You: Oh, I can overnight at my own expense. It’s fine for you to document the weather. I’m actually really scared of the aircraft that flies non-stop to Atlanta, and I can stay with the friend that I’m delivering documents to anyway.

Agent: Oh wait, there actually is a later flight that day I’ll put you in it and you’ll get into Atlanta late at night. (Indian call center agent actually puts you on the late flight the enxt day but you don’t complain to United about the poor service and how they got you stuck in DC, since you didn’t plan to fly to Atlanta anyway…)

By the way for the United folks who read this blog, this is an entirely made up scenario. If you pull up my account or ticketing history you’ll see that I’ve never actually flown (and not flown) these flights. It could have been any other carrier and any other made up route.

Ninety percent of the time though this comes off without a hitch and you get real savings. It’s a technique for the bag of tricks, one of many.

Related to hidden city ticketing is throwaway ticket, traditionally though of not as just throwing away the last leg of an itinerary but booking a roundtrip instead of a one-way ticket and not using the return.

It’s very rare in the U.S. that this saves you money anymore.. A large chunk of fares are one-way these days anyway, and those that aren’t rarely price a one-way at much more than half a roundtrip cost, and certainly not more than a roundtrip cost.

Europe though is a different beast entirely. European flag carriers often price one-ways automatically as full fare, so a London – Frankfurt one-way might be over $700 but a London – Frankfurt roundtrip taking the exact same outbound flight could be $250. Whenever I need to buy intra-European one-way tickets I always compare the one-way price to roundtrip. This is sometimes the case in Asia as well, and especially with European carriers flying tag flights, short hops between Asian destinations.

Have you done throwaway ticketing? What routes work out best for you? Have you ever gotten heat from an airline over the practice? I’d appreciate your experiences.