Is it cheaper to buy individual flights for transit flights that requires travelling in different airlines ?

Answer 1

Sometimes it's cheaper, sometimes it's not, but it's really not the best idea in the world even if you save some money. If you buy the tickets from one airline and they have to put you on another airline's plane for part of the trip, you are still under the same record and itinerary number. If you make separate purchases, then you get separate record numbers. And if something goes wrong--- mechanical problems, weather, etc--- if you have one itinerary/record # all the way through, it is a lot easier for you to get taken care of than if your records are separate.

Here's an example:

You live in Virginia and you want to go to Ireland. You take a United flight to JFK in NY, then an Aer Lingus flight to Dublin (I don't even know if these airlines fly to these cities--- just making an example). On your trip home, your flight from Dublin back to NY is delayed due to a mechanical problem and that causes you to miss your NY-VA flight.

If you purchased one trip from United and United routed you through Aer Lingus, then United will be of some assistance in getting you on another flight when you get to NY, and possibly hotel for the night. If you purchased one ticket from United and another from Aer Lingus, you're out of luck--- Aer Lingus will say, we did our job, we took you from NY to Dublin and back, and since your ticket doesn't show any other stops after NY, we won't give you a hotel because you've made it back to where you started. And United will say, you didn;t show up for your NY-VA flight so we owe you nothing; it's not United's fault if Aer Lingus messed up. They might even make you pay for another ticket!