Originally Posted by
dlichterman
There is an earlier flight and I am trying to understand the same day change rules - looks like there would be a $75 fee for switching, if there was space(
https://www.united.com/ual/en/br/fly...-change.html)? I am only a member, no status. Fare class is P. Do I not check in until I know what flight I will want to take?
Checking in won't matter unless you're checking luggage, but the current same-day change policy for non-status members is.. murky. With the elimination of change fees in general, it's not exactly clear what's covered by the policy and what isn't. You may be charged $75 or you may be charged a fare difference. Note that to have any chance of getting a discount change, P inventory needs to be available because that's what you booked. If you try to fly standby, you will likely end up in economy, because they will clear upgrades before they would clear standby passengers. SDC page at FlyerTalk, with wiki:
UA Same-Day Travel Change (SDC) Fees/Questions -Free STBY for all, SDC for all elites
Originally Posted by
dlichterman
Lets say the worst happened and I am either stuck or extremely delayed - what are my options? Will I have luck asking to move the flight? Or should I just get a credit for the portion unflown? As long as I don't check in, I can cancel for a credit, right?
(a) to whatever extent same-day change works to allow you to move to an earlier flight, you can also use it to move to a later flight, as long as both flights -- your current and your target flight -- are less than 24 hours away
(b) UA may, but is not obligated to, move you to the next flight under the "flat-tire rule," an unpublished rule that's intended to cover unexpected delays on the way to the airport. Flying into the airport ton a competitor isn't really supposed to count, though.

(c) You can cancel for a credit any time prior to the being marked a no-show. Checking in does not forfeit that right.