Originally Posted by
Flying for Fun
I haven't had issues doing a SDC on multi-segment itineraries when the subsequent segments are outside 24 hours. It wouldn't make sense to SDC ORD-SEA to a later time when that departure is after the subsequent segment SEA-GEG. Once the SDC is processed, you won't be able to check-in for the later itinerary until 24 hours before departure. If it is an earlier flight, you can continue with check-in.
A minor update on this - it seems AS IT is a bit inconsistent.
I had a W fare that I purchased with miles because it was close in, so I got the cheapest fare of the day and did an SDC at check-in to the flight I wanted, which was about 12 hours later. At check-in time for the original flight, I did an SDC to the later flight using the web interface. It made the SDC, but then when I went to check in for the new flight, it threw an error and told me to check in at the airport. A few minutes on the phone with a very pleasant agent fixed it. Note that I did get an upgrade for the original flight, but not for the new one, which seemed to have F filled with people on package deals returning from Cabo, based on overheard conversations.
Second flight (separate PNR - I bought two one ways for this trip), I checked in with the app about 2 hours after the check-in time for the original flight, and still about 6 hours early for check-in on the later flight that I wanted. It *did* let me check-in for the later flight and gave me a mobile BP. Oddly, it still shows me as on the PC and F upgrade lists, even though I'm already in a PC seat. We'll see what happens at the regular check-in time when I try to check in again and generate a bag tag.
I think this is my first real attempt at SDC since making MVPG last fall.
ETA: oddly - the purchased fare class was Q, but now when I look after doing the SDC it's showing Y. I had already been upgraded on the original flight, so maybe they promoted me to Y when I took the downgrade to get a later flight?