Fare hacking – what airlines don’t really want you to know

Previously we looked at quick and simple ways to find cheap flights. If you’re really committed in getting the cheapest flights however, you’ll run into what’s known as “fare hacking”. No, this doesn’t involve breaking into their computer systems or doing anything illegal. It’s hacking in the sense that you purchase tickets that the airlines have made freely available, but take advantage of some pricing idiosyncrasies that perhaps the airline itself didn’t intend to exist.

Sounds mysterious? Let’s take a step back.

Previously we discussed that airlines have different fare buckets and fare structures and your fare is based on a combination of your destination, channel of purchase, timing of purchase as well as any fare restrictions. The airlines offer these fare buckets and structures to try and maximise their revenue which might not correspond to how much the ticket costs. Furthermore complex systems that manage these fares and airlines are constantly managing a large number of fares, anomalies can also occur outside of their expectation. This means that airline pricing doesn’t always make logical sense – longer flights could cost less than a short flight, more destinations could be cheaper, and you might not always be rewarded by flying with the same airline the whole way.

Here’s a simple example. Doing a search for a round trip from Seattle to London costs 1660.56 US Dollars. However, if you happen to go the other way from London to Seattle, also on a direct flight operated by Virgin Atlantic, it would only be 838.57 Pounds which is about 1060 US Dollars. These are flights departing at the same time on the same day of the week and operated by the same airline, only swapped around, so you would expect the price to be quite similar. However, you get a $600 dollar difference, almost 60% extra just because you happen to be flying the other way!

Flight from LHR to SEA

Flight from SEA to LHR

Most people can’t magically start your trip in another location and fly the other way. Airlines take advantage of this fact. So in the example, the traveller going from might just end up paying whatever it costs.

However, consider a second scenario: a business traveller that has to make a trip from Seattle to London a 2nd time in August on a Thursday again.

Introducing: Nested Ticketing

The second trip has come back at $1535.56 to the trip making the total cost of 2 trips $3196.12.


There’s actually another way to purchase tickets to travel the same legs over the 2 months. Instead of booking a return flight from Seattle to London in July and another in August, we can book one return flight from Seattle to London departing in July and returning in August, and a 2nd return flight from London to Seattle

Ticket Leg Date
Ticket 1 Seattle to London 1 June 2017
London to Seattle 7 June 2017
Ticket 2 Seattle to London 3 Aug 2017
London to Seattle 10 Aug 2017


Ticket Leg Date
Ticket 1 Seattle to London 1 June 2017
Ticket 2 London to Seattle 7 June 2017
Ticket 2 Seattle to London 3 Aug 2017
Ticket 1 London to Seattle 10 Aug 2017


Let’s see how much this costs.

Ticket 1: SEA to LHR with the return leg at the end of the 2nd journey

Ticket 2: LHR to SEA nested within the first ticket

In the 1st ticket, the cost is $1660.56 which is about the same as the typical Seattle to London flight, however, we get savings in the 2nd ticket which is about $1020 USD making the total of 4 legs around $2680. By taking a round trip ticket and nesting a round trip ticket within it, we can take advantage of the fact that going in one direction is cheaper. This is a saving of around $500, compared to booking two back to back round trip tickets which would set you back $3196.12.

You might wonder whether there are any disadvantages to booking a nested round trip ticket. There is a minor consideration – if your flight plans change – for example the 2nd trip to London is cancelled – then you end up having to make changes to the first flight and cancel the second, whereas if the booking was only for the first flight then you would have only required to cancel the 2nd flight. This could mean a change fee, if change of dates is possible at all. As always, check the fare conditions of the ticket before booking.


Hidden city ticketing

Earlier we already established that airlines used some complex systems to manage their fares, depending on supply seat and passenger demand. What’s bizarre is that sometimes you might find two identical routes, except one has one or more legs at the end of the journey, but costing less overall.

There could be several reasons to this: airlines might want to encourage customers to go to a particular destination (so that maybe they’ll take another flight from that destination), or perhaps they just want to fill up seats on a flight.

Regardless, this is something you can take advantage of. You book the airfare with the additional travel, and your target destination is just a stop on the route. However, you just don’t get on the plane for the part of the journey you don’t need. This is known as “Hidden city ticketing”.
There are plenty of routes where you can apply this technique. Here is one example.

In this example I did a search for on the Delta airlines for a flight from JFK to ATL. It came up as 193.20 USD.


The flight from JFK to JAX stopping over at ATL costs only 148.80 USD


You might wonder, how you can find these hidden city airfares. While you could manually try different combinations of travel with your target destination as a stopover, Skiplagged does exactly just this as for you automatically. You enter your departure and destination city as per usual and it automatically searches for fares, including tickets with hidden ticketing. It searches for normal fares as well, so if the cheapest fare doesn’t involve hidden ticketing then you it still presents you with that option. Once you’ve done this it also provides you with instructions on booking the fare. It’s pretty convenient overall.

There are a few caveats that you need to be mindful:

Firstly, you can’t check bags. Checked bags will end up at the final destination. Carry-ons are fine, however there are scenarios where the bag won’t fit under the seat in front of you, there is not enough cabin space, or for some other reason you’re forced to check your bag.

Secondly, it’s not encouraged by airlines and it could be against their ticket terms to intentionally miss a leg. They might penalise you in some way, for example invalidate any mileage points you’ve accrued with them.

In rare times of irregular operations such as bad weather, your itinerary may change at the discretion of the airline. For example, they might fly you to your destination via another route.

Any of these could be quite disruptive your travel plans, so you’ll have to consider whether the savings is worth the risk and also have a contingency to manage your risk.