Will boarding a two-leg flight at the stopover airport cause any problems?

Question

Recently, I purchased a two-leg plane ticket from New York City (LGA) via Philadelphia (PHL) to my final destination (which we'll call XYZ). I happened to be coming from a place from which it wasn't very much harder to get to PHL than to get to LGA. This being the case, I very much wanted to just purchase a ticket from PHL to XYZ and call it a day, but for whatever reason, the PHL-XYZ ticket by itself cost something like twice as much as LGA-PHL-XYZ, so I ended up buying the latter.

This brings me to my question: having purchased the LGA-PHL-XYZ ticket, could I simply forgo the LGA-PHL leg and head straight to PHL to catch my flight to XYZ? Would this cause any problems (e.g. with the TSA or whatnot)?

Answer 1

If you miss the first leg of your trip, you will be treated as a "no-show" and the rest of that trip will be cancelled.

If you had a flight XYZ-PHL-LGA and wanted to get off at PHL without finishing the journey, that is okay because you don't need the rest of the trip anyway. Most of the time, your seat will be given to someone on standby. If you have checked luggage, it might take some time to retrieve. This is also a good way to lose your checked luggage... :)

Sometimes, sneaky travel agents can actually save you money by making these kind of tickets, where you are booked onto flights that you will never use, just because the airline has a campaign that ends up cheaper than a normal fare. The airlines don't generally like this, and it is always at your own risk.