Originally Posted by
orbitmic
Actually there are tons of different reasons why you may want or need to travel on separate pnrs. For some itineraries single pnrs are impossible to get through the airline's website itself and they are the ones making it prohibitive to book through the phone and impossible to book at a ticket office since those have disappeared. Other itineraries simply won't price as single pnrs when flying specific airlines and/ or flights. Then what if you're travelling with someone but with slight variations (e.g pax 1 cdg lax cdg, pax 2 cdg lax cdg nce). If you want to be on the same pnr for the long haul (eg to extend ff benefits to the other) your only choice is a separate pnr for the cdg nce even though this will add to your cost. Or again you thought you needed to go to cdg but end up having to go to Lhr instead for an impromptu meeting. There are many other configurations most of which entirely legitimate and I think airlines should offer interlining whenever possible.
If I may be the contrarian (as per usual

), the difference between separate tickets/reservations and same ticket/reservation is that the cost of handling the interlining of baggage (=mostly the risk of misconnect) is included in the latter whereas it is not in the former.
Yes, there may be a gazillion reasons why one books on separate tickets but it does not follow from this that this entitles one to shift the cost and risk of interlining onto the airline.
In an ideal world, there should be some kind of possibility to "buy" interlining on separate tickets as an additional service. I guess, though, that there would be a high chance an adverse selection issue here that would make it more expensive than it should be.
There are quite a few arguments that I do not buy here:
1) that you often cannot buy tickets on different airlines on an airline's website: true but there are alternative channels;
2) alternative channels or phone call centres are prohibitively expensive: they are a little more expensive but given that you get interlining thrown in, there is something problematic about complaining about the few extra euros you have to pay for using a channel rather another;
3) fares cannot be combined resulting in hugely expensive fares: true, but what this means is that the airline has chosen NOT to offer through-tickets at discount fares on a certain itinerary. Yet, what you are trying to do is to force the airline to offer a de facto through service.
It seems to me that, to be logically coherent, if one states that airlines should accept baggage for interlining on separate tickets, then they should equally be responsible for passenger misconnects (and not just passenger baggage misconnects) on separate tickets (provided that the MCT is observed).
I have not seen many people arguing for the latter, therefore I am puzzled that people think that it is inappropriate for airlines to move away from offering the former.
Don't get me wrong: I fully appreciate the value of interlining on separate tickets and have benefited from it every now and then. But I would find it difficult to blame the airlines for moving away from it. It was good while it lasted but if it comes to an end, so be it.