Jan 4, 2015, 2:01 pm
Last edit by: WineCountryUA
This wiki was created to distill SDC (and related standby) down to a set of rules in the hopes of benefiting others.
The official "rules" can be found here. In practice, some of the rules almost always apply, and some are more flexible.
Note there have been reports of SDC to one segment removing confirmed CPU upgrades on downline segments. If maintaining the confirmed upgrade is important then these changes should be handled with care.
Most Frequently Asked Question: When do I call/go online to make the change?
Follow this flowchart:
Question 1: Are you within 24 hours of your currently scheduled UA(*) operated flight that you're trying to change off of? If yes, continue to Question 2. If no, continue to answer 1.
Question 2: Are you within 24 hours of the first UA operated flight you're trying to change on to? If yes, continue to to Answer 2. If no, continue to Answer 1.
Answer 1: No, you cannot call/go online yet to make an SDC.
Answer 2: Yes, then you can call/go online to make an SDC.
General Baseline Rules
These are the general rules that usually apply to SDC's; falling outside these rules usually requires payment of a full change fee and the fare difference:
How to SDC
SDC can be accomplished in a few different places (in rough order of likelihood of being able to get the rules bent):
Please note that the United.com “change flight” link before checking in within T-24, is broken. The website may not show all available options and will often attempt to collect the change fee rather than the SDC fee (if any).
NB: An SDC where the original itinerary (in one direction) has three or more segments cannot be done online.
Nuances and Loose Rules
Now for the hard part: figuring out where the flexibility is in the rules. This list is compiled from the responses to people saying "Can I do X?" where X is something that is not clearly permitted by the rules. One's likelihood of success here depends a bit on the method used for the SDC.
For each item, the following codes apply:
Y = officially permitted and possible using any method
A = not permitted but perhaps possible using an agent (phone/counter), perhaps having to HUACA
A* = mixed reports of success with an agent (phone/counter),
N* = possible only if you find a very accommodating agent
N = little or no reported success.
If you encounter issues with an agent (phone or counter/gate), you can ask the agent to reference GG SDC. Additionally, GG SDC line 61 specifically references that fare classes are supposed to level out 3.5 hours before departure, so you might be able to use that to your advantage if fare classes have not leveled out and you're trying to ask an agent to open up the correct inventory or force you onto the flight.
Note -- as of 11/27/2017: A datapoint indicates that UA may have updated its GG rule regarding leveling out to state the following:
Standby
You may stand by if seats are not available in the purchased fare class. In these cases, the same-day change fee will apply, but will not be charged unless you are assigned a seat on your alternate flight. Changes in routing are not allowed when standing by. Standby may be requested on the day of departure at an airport kiosk or with a United representative at the airport. Once you are added to the flight standby list, you can check your real-time standby status at united.com/flightstatus or on your mobile device at mobile.united.com/info.
Instead of paying a same-day change discounted fee, can I stand by for my desired flight for free?
No. The only time you may standby for free is when the fare does not have any penalties for making changes, or when standing by involuntarily due to a flight irregularity.
Can I pay the same-day change discount fee with cash?
Cash will only be accepted by a United airport representative when the change is available to be confirmed, not for standby travel.
original posting by mgcsinc, initiated by jackal
Previous threads:
UA Same-Day Travel Change (SDC) Fees/Questions *now with WikiPost* {pre-2015 Archive}
The official "rules" can be found here. In practice, some of the rules almost always apply, and some are more flexible.
Note there have been reports of SDC to one segment removing confirmed CPU upgrades on downline segments. If maintaining the confirmed upgrade is important then these changes should be handled with care.
Most Frequently Asked Question: When do I call/go online to make the change?
Follow this flowchart:
Question 1: Are you within 24 hours of your currently scheduled UA(*) operated flight that you're trying to change off of? If yes, continue to Question 2. If no, continue to answer 1.
Question 2: Are you within 24 hours of the first UA operated flight you're trying to change on to? If yes, continue to to Answer 2. If no, continue to Answer 1.
Answer 1: No, you cannot call/go online yet to make an SDC.
Answer 2: Yes, then you can call/go online to make an SDC.
General Baseline Rules
These are the general rules that usually apply to SDC's; falling outside these rules usually requires payment of a full change fee and the fare difference:
- The departure time of the first segment of the old itinerary and the departure time of the first segment of the new itinerary must both be within 24 hours of the moment that the change is made.
- Only applies to UA/UX operated flights, domestic or international. Changing from a non-UA operated to UA operated may be possible.
- The ultimate origin and destination airports must remain the same.
- Routing can be changed (addition, deletion, or change of connection points) but the routing rules of the original fare usually apply.
- All remaining unflown segments in single fared itinerary are considered together (i.e., if you're flying WWW-XXX-YYY-ZZZ, you can go to a kiosk at XXX and potentially fly XXX-AAA-ZZZ or XXX-ZZZ direct).
- SDC can be done an unlimited number of times, and can therefore be used to extend a trip indefinitely (pending availability).
- SDC costs $75 for Members and Silvers - the fee is waived for Golds and up (plus any applicable fare difference, see below). *G's may also get free SDC, although there is no mention of this in the official rules. Once in-route, fees for an earlier connecting flight may be waived per GG SDC Line 118.
- Non-elites on the same PNR benefit from any waived fees for SDC.
- No fare difference is charged so long as there is availability on all of the new segments in the originally ticketed fare class. Fare class availability in all classes often opens up after T-24 and almost always opens up at T-3 unless the plane is very full.
- SDC on bulk tickets, including United Specials, is not permitted.
- SDC is permitted on both domestic and international itineraries.
How to SDC
SDC can be accomplished in a few different places (in rough order of likelihood of being able to get the rules bent):
- United mobile app
- Kiosk
- Phone
- On united.com, right now only the "Search Other Flight Options" button during On-Line Check-In (OLCI) works. This has spotty availability, particularly if the change would involve paying an additional fare due to fare bucket non-availability.
- Counter/Gate (although reports are that most airport agents are not familiar with the SDC policy and may not allow you to SDC to a valid itinerary--you can try to direct them to look up GG SDC, but they often won't understand that what you're trying to do is permitted by those rules)
NB: An SDC where the original itinerary (in one direction) has three or more segments cannot be done online.
Nuances and Loose Rules
Now for the hard part: figuring out where the flexibility is in the rules. This list is compiled from the responses to people saying "Can I do X?" where X is something that is not clearly permitted by the rules. One's likelihood of success here depends a bit on the method used for the SDC.
For each item, the following codes apply:
Y = officially permitted and possible using any method
A = not permitted but perhaps possible using an agent (phone/counter), perhaps having to HUACA
A* = mixed reports of success with an agent (phone/counter),
N* = possible only if you find a very accommodating agent
N = little or no reported success.
- Violating various non-routing fare rules (day/time, minimum stay, etc.): Y
- Change destination to ultra-close airport (see the old S*FAR/STANDBY): A
- Change destination to a co-terminal: N*
- Change destination to an entirely different place: N
- Change itinerary at the beginning to include illegal layovers (> 4 hours): N*
- Change itinerary at the layover point (using kiosk, app, or agent) to create an otherwise illegal layover: Y
- Change itinerary at the beginning to add a layover point not permitted by the routing rules: N*
- Change itinerary at a layover point to add another layover not permitted (either in terms of number of segments or routing rules) by the routing rules: Y
- Change to a flight exactly 24 hours before or after the original flight: N*
- Change to a flight exactly 24 hours before the original flight, if the previous day's flight has been delayed: Y (based on one report)
- Combining separately-fared segments to do SDC (e.g. XXX-YYY+YYY-ZZZ -> XXX-ZZZ): A
- Change UA-codeshare, non-UA-metal segment to UA metal: A
- Change from UA metal to UA-codeshare, non-UA-metal segment: N (see post 1813 for one exception)
- Change from UA-codeshare, non-UA-metal segment to a different UA-codeshare, non-UA-metal segment: ??
- Change on a non-UA ticketed segment: N* (with potential dire consequences)
- Change from an upgraded flight into Y on the new flight: Y
- Change from a GPU-upgraded flight into J/F on the new flight: A
- Change from a CPU-upgraded flight and get confirmed into available R space on the new flight: N*
- Change from an instrument-upgraded flight and get confirmed into available R space on the new flight: A*
- Non-elite on different PNR benefiting from Elite's waived-fee SDC: A
- Change at origin airport after tendering a checked bag: N
- Change at layover airport when a bag has been checked: N
If you encounter issues with an agent (phone or counter/gate), you can ask the agent to reference GG SDC. Additionally, GG SDC line 61 specifically references that fare classes are supposed to level out 3.5 hours before departure, so you might be able to use that to your advantage if fare classes have not leveled out and you're trying to ask an agent to open up the correct inventory or force you onto the flight.
Note -- as of 11/27/2017: A datapoint indicates that UA may have updated its GG rule regarding leveling out to state the following:
Code:
EVERYDAY AWARD AND REVENUE BUCKETS ARE TO LEVEL OUT WITHIN 2H OF DEPARTURE
You may stand by if seats are not available in the purchased fare class. In these cases, the same-day change fee will apply, but will not be charged unless you are assigned a seat on your alternate flight. Changes in routing are not allowed when standing by. Standby may be requested on the day of departure at an airport kiosk or with a United representative at the airport. Once you are added to the flight standby list, you can check your real-time standby status at united.com/flightstatus or on your mobile device at mobile.united.com/info.
Instead of paying a same-day change discounted fee, can I stand by for my desired flight for free?
No. The only time you may standby for free is when the fare does not have any penalties for making changes, or when standing by involuntarily due to a flight irregularity.
Can I pay the same-day change discount fee with cash?
Cash will only be accepted by a United airport representative when the change is available to be confirmed, not for standby travel.
original posting by mgcsinc, initiated by jackal
Previous threads:
UA Same-Day Travel Change (SDC) Fees/Questions *now with WikiPost* {pre-2015 Archive}
UA Same-Day Travel Change (SDC) Fees/Questions (with Wiki) {Archive}
Jan 25, 2018, 2:21 pm
#3196
Join Date: Jan 2008
Location: EAU
Programs: UA 1K, CO Plat, NW Plat, Marriott Premiere Plat, SPG Plat, Priority Gold, Hilton Gold
Posts: 4,712
I would be shocked if you found a UA agent willing to allow you to standby for a later flight from a remote station. Once the departure time passes for your original flight, your downline segments -- including the standby segment -- would be cancelled and need to be reconstituted anyway. I doubt an agent is going to want to help you get stuck at BBB.
Jan 25, 2018, 2:33 pm
#3197
FlyerTalk Evangelist
Join Date: Oct 2001
Location: Austin, TX
Posts: 21,359
While I also wouldn't be surprised if SDC requests were limited to the airport where those flights originate, I'm not sure I follow your logic here... You seem to be saying that if you stand by for a later flight, then are not present for your initial flight, that your flights cancel out - this is not true. Once you are on standby for the later flight, you don't have to be present for the initial flight.
If you're suggesting that you could convince an agent to remove your current, confirmed seat from your record and put you onto standby on another (later) flight, without any confirmed seat at all -- sure, I'll grant that, in that scenario, you wouldn't be penalized for missing your original (confirmed) flight, because it would already have been removed from your record. But I'm having a hard time imagining an agent agreeing to do what you're asking. (Frankly, I'm not sure they'd understand what you're asking). And, if you failed to clear the standby list on the flight you wanted, I guess you'd roll over to the next departure as though you were in an IRROPS / flat tire situation. But that's just a guess -- it's entirely possible that they could tell you that your ticket is no longer valid and you have to buy a walk-up ticket if you still want to travel. Mostly, I think you're just going to confuse people if you try this.
Jan 25, 2018, 3:26 pm
#3198
Join Date: Apr 2003
Location: IAD/DCA
Programs: UA 1K/MM, Marriott Pltm, Hyatt Diamond, spg Pltm
Posts: 356
I dont know if it's been discussed: the meaning of "within 24 hours of the original departure". If I miss the original departure, but still within 24 hours of it, can I do an SDC?
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
Jan 25, 2018, 3:31 pm
#3199
FlyerTalk Evangelist
Join Date: Oct 2006
Location: SFO/SJC
Programs: UA Silver, Marriott Gold, Hilton Gold
Posts: 14,880
I dont know if it's been discussed: the meaning of "within 24 hours of the original departure". If I miss the original departure, but still within 24 hours of it, can I do an SDC?
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
Jan 25, 2018, 6:40 pm
#3200
Join Date: Jan 2008
Location: EAU
Programs: UA 1K, CO Plat, NW Plat, Marriott Premiere Plat, SPG Plat, Priority Gold, Hilton Gold
Posts: 4,712
Well, typically, it's not possible to standby for a flight that's later than your scheduled departure. It's an implicit assumption underlying all of the rules and procedures governing standby -- you standby for an earlier flight and your confirmed flight is a backup. Strictly speaking, I don't even know how you could standby for a later flight and still keep your initial flight -- I'm not sure what it would mean.
If you're suggesting that you could convince an agent to remove your current, confirmed seat from your record and put you onto standby on another (later) flight, without any confirmed seat at all -- sure, I'll grant that, in that scenario, you wouldn't be penalized for missing your original (confirmed) flight, because it would already have been removed from your record. But I'm having a hard time imagining an agent agreeing to do what you're asking. (Frankly, I'm not sure they'd understand what you're asking). And, if you failed to clear the standby list on the flight you wanted, I guess you'd roll over to the next departure as though you were in an IRROPS / flat tire situation. But that's just a guess -- it's entirely possible that they could tell you that your ticket is no longer valid and you have to buy a walk-up ticket if you still want to travel. Mostly, I think you're just going to confuse people if you try this.
If you're suggesting that you could convince an agent to remove your current, confirmed seat from your record and put you onto standby on another (later) flight, without any confirmed seat at all -- sure, I'll grant that, in that scenario, you wouldn't be penalized for missing your original (confirmed) flight, because it would already have been removed from your record. But I'm having a hard time imagining an agent agreeing to do what you're asking. (Frankly, I'm not sure they'd understand what you're asking). And, if you failed to clear the standby list on the flight you wanted, I guess you'd roll over to the next departure as though you were in an IRROPS / flat tire situation. But that's just a guess -- it's entirely possible that they could tell you that your ticket is no longer valid and you have to buy a walk-up ticket if you still want to travel. Mostly, I think you're just going to confuse people if you try this.
If you want to take a later flight than the one you have scheduled, and seats in your fare class are not available, they add you to Stand-By for the later flight you want to be on. I don't know for sure what they do with your original booking, but whatever they do, missing that flight has no effect on the rest of your itinerary. It's no different than having a flight cancel due to IRROPS and there not being seats available on later flights so they put you on standby for that.
The risk, of course, is that once you put yourself on a standby ticket, you're not getting on a flight until there's empty seats.
There is, however, no risk at all of losing your ticket by attempting to standby for a later flight.
Anyway, you don't need to guess, or assume, or other wise wonder how it works - you can absolutely same-day standby for a later flight.
I dont know if it's been discussed: the meaning of "within 24 hours of the original departure". If I miss the original departure, but still within 24 hours of it, can I do an SDC?
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
As many have mentioned, generally it's a NO, as your entire reservation will disappear when you miss any segment. However, we all know at least in the same day the reservation can still be seen by UA agents, and I had several times by calling UA to reinstate the res. and confirm to a later flight. Of course that's only within a short while of the departure of the original flight, but usually it had to be done at the airport (the famous "flat tire excuse"). But now definitively it can be done by calling UA.
As a practical matter, this means if you time your request right, you can same day change to any flight that leaves from about 23 hours before your originally scheduled departure to about 23 hours after. You can also same day standby to any flight that has the same routing within that time frame. Free same day changes for gold+ is what I consider the best benefit of the United frequent flyer program and is pretty much THE reason I stick with United.
If you simply fail to show up for your flight, it will automatically cancel, but the few times I've accidentally done that, and I got in touch with United just afterwards (usually sometime between just after the check-in deadline to less than an hour after the flight), they've just put me standby on the next flight. YMMV. I certainly wouldn't just ignore the flight and attempt to get another flight hours later.
Short version, while the app and kiosk will lock you out of SDC after the check-in deadline, an agent will probably still do it for you for some short time period after departure.
Jan 25, 2018, 7:48 pm
#3201
FlyerTalk Evangelist
Join Date: Oct 2001
Location: Austin, TX
Posts: 21,359
I can assure you that, at least as far as United is concerned, you can ABSOLUTELY stand-by for a later flight. Forget typical or implicit or whatever, you can do it and it's part of their SDC/stand-by policy and there is nothing odd about it. I have done it many times.
If you want to take a later flight than the one you have scheduled, and seats in your fare class are not available, they add you to Stand-By for the later flight you want to be on. I don't know for sure what they do with your original booking, but whatever they do, missing that flight has no effect on the rest of your itinerary. It's no different than having a flight cancel due to IRROPS and there not being seats available on later flights so they put you on standby for that.
The risk, of course, is that once you put yourself on a standby ticket, you're not getting on a flight until there's empty seats.
There is, however, no risk at all of losing your ticket by attempting to standby for a later flight.
Anyway, you don't need to guess, or assume, or other wise wonder how it works - you can absolutely same-day standby for a later flight.
If you want to take a later flight than the one you have scheduled, and seats in your fare class are not available, they add you to Stand-By for the later flight you want to be on. I don't know for sure what they do with your original booking, but whatever they do, missing that flight has no effect on the rest of your itinerary. It's no different than having a flight cancel due to IRROPS and there not being seats available on later flights so they put you on standby for that.
The risk, of course, is that once you put yourself on a standby ticket, you're not getting on a flight until there's empty seats.
There is, however, no risk at all of losing your ticket by attempting to standby for a later flight.
Anyway, you don't need to guess, or assume, or other wise wonder how it works - you can absolutely same-day standby for a later flight.
I suppose that there's no technical reason that they can't delete a confirmed segment from your record and replace it with a waitlisted one. I'm just surprised that it's such an easy ask. :-)
Jan 25, 2018, 9:57 pm
#3202
Join Date: Jan 2008
Location: EAU
Programs: UA 1K, CO Plat, NW Plat, Marriott Premiere Plat, SPG Plat, Priority Gold, Hilton Gold
Posts: 4,712
I'm hesitant to argue with you, since you're obviously speaking from experience. I'm fairly certain that you've been done a favor -- maybe the same favor, multiple times, but a favor nonetheless. They're essentially applying the flat-tire rule in advance -- which is, itself, a favor, although one that's routinely granted. Normally, though, with the flat-tire rule, they'll put you into a confirmed seat -- into positive space if they're feeling generous, or into the first available seat in your fare class if they're not. Either way, you could then standby for an earlier flight than you're confirmed on. (Incidentally, that's how IRROPS works, too -- you're not just put onto standby; you're confirmed onto the first available alternative and can then standby for others).
I suppose that there's no technical reason that they can't delete a confirmed segment from your record and replace it with a waitlisted one. I'm just surprised that it's such an easy ask. :-)
I suppose that there's no technical reason that they can't delete a confirmed segment from your record and replace it with a waitlisted one. I'm just surprised that it's such an easy ask. :-)
If you read United's policy on the issue, while it's a bit ambiguous as to whether you can same-day standby across calendar days, it otherwise seems to imply you can same-day standby for any flight you could same-day change to (if there was inventory), which would include flights after your original flight.
I see nothing on the United Same Day Change policy page that indicates Same Day Standby is only available for flights before your original flight.
Jan 26, 2018, 11:53 am
#3203
Join Date: Mar 2016
Location: IAH
Programs: UA Gold
Posts: 73
Changing UA segment of flight bought on United stock with *A segment
Thought this was already answered in the wiki, but turns out I don't see it: You should be able to SDC a UA flight with *A segments at the layover point as long as you're only trying to change the UA segment and the ticket is issued on UA stock right?
i.e. I have
BKK-NRT on ANA
NRT-SFO on UA
SFO-IAH on UA
and I want to SDC the SFO-IAH part. I should have no problem doing that after I land in SFO right?
Edit: Thanks EmailKid and findark for the replies!
i.e. I have
BKK-NRT on ANA
NRT-SFO on UA
SFO-IAH on UA
and I want to SDC the SFO-IAH part. I should have no problem doing that after I land in SFO right?
Edit: Thanks EmailKid and findark for the replies!
Last edited by raycosm; Jan 26, 2018 at 12:16 pm
Jan 26, 2018, 12:01 pm
#3204
Moderator: Budget Travel forum & Credit Card Programs, FlyerTalk Evangelist
Join Date: Aug 2002
Location: YYJ/YVR and back on Van Isle ....... for now
Programs: UA lifetime MM / *A Gold
Posts: 14,426
Jan 26, 2018, 12:03 pm
#3205
FlyerTalk Evangelist
Join Date: Nov 2014
Location: MSP
Programs: DL PM, UA Gold, WN, Global Entry; +others wherever miles/points are found
Posts: 14,392
Correct, as long as it is an 016 ticket.
Jan 26, 2018, 3:25 pm
#3207
A FlyerTalk Posting Legend
Join Date: Apr 2013
Location: PHX
Programs: AS 75K; UA 1MM; Hyatt Globalist; Marriott LTP; Hilton Diamond (Aspire)
Posts: 56,416
Jan 26, 2018, 3:32 pm
#3208
Join Date: Apr 2003
Location: IAD/DCA
Programs: UA 1K/MM, Marriott Pltm, Hyatt Diamond, spg Pltm
Posts: 356
I did not read all your posts, but how practically to standby a later flight without showing up at the airport for the original flight? Can you just call from anywhere? The only thing for sure is that no matter what you do, you do it before the original flight departs (or 30 minutes before that). Will then the app show the new (standby'd) flight?
I can assure you that, at least as far as United is concerned, you can ABSOLUTELY stand-by for a later flight. Forget typical or implicit or whatever, you can do it and it's part of their SDC/stand-by policy and there is nothing odd about it. I have done it many times.
If you want to take a later flight than the one you have scheduled, and seats in your fare class are not available, they add you to Stand-By for the later flight you want to be on. I don't know for sure what they do with your original booking, but whatever they do, missing that flight has no effect on the rest of your itinerary. It's no different than having a flight cancel due to IRROPS and there not being seats available on later flights so they put you on standby for that.
The risk, of course, is that once you put yourself on a standby ticket, you're not getting on a flight until there's empty seats.
There is, however, no risk at all of losing your ticket by attempting to standby for a later flight.
Anyway, you don't need to guess, or assume, or other wise wonder how it works - you can absolutely same-day standby for a later flight.
The policy is, anytime from 23 hours and 59 minutes prior to your scheduled departure up until 30 minutes prior to your scheduled departure (sooner at some airports, it's whenever the check-in deadline is), you can request to same day change to any flight with the same origin and destination that is departing within 23 hours and 59 minutes of the time you are making the request.
As a practical matter, this means if you time your request right, you can same day change to any flight that leaves from about 23 hours before your originally scheduled departure to about 23 hours after. You can also same day standby to any flight that has the same routing within that time frame. Free same day changes for gold+ is what I consider the best benefit of the United frequent flyer program and is pretty much THE reason I stick with United.
If you simply fail to show up for your flight, it will automatically cancel, but the few times I've accidentally done that, and I got in touch with United just afterwards (usually sometime between just after the check-in deadline to less than an hour after the flight), they've just put me standby on the next flight. YMMV. I certainly wouldn't just ignore the flight and attempt to get another flight hours later.
Short version, while the app and kiosk will lock you out of SDC after the check-in deadline, an agent will probably still do it for you for some short time period after departure.
If you want to take a later flight than the one you have scheduled, and seats in your fare class are not available, they add you to Stand-By for the later flight you want to be on. I don't know for sure what they do with your original booking, but whatever they do, missing that flight has no effect on the rest of your itinerary. It's no different than having a flight cancel due to IRROPS and there not being seats available on later flights so they put you on standby for that.
The risk, of course, is that once you put yourself on a standby ticket, you're not getting on a flight until there's empty seats.
There is, however, no risk at all of losing your ticket by attempting to standby for a later flight.
Anyway, you don't need to guess, or assume, or other wise wonder how it works - you can absolutely same-day standby for a later flight.
The policy is, anytime from 23 hours and 59 minutes prior to your scheduled departure up until 30 minutes prior to your scheduled departure (sooner at some airports, it's whenever the check-in deadline is), you can request to same day change to any flight with the same origin and destination that is departing within 23 hours and 59 minutes of the time you are making the request.
As a practical matter, this means if you time your request right, you can same day change to any flight that leaves from about 23 hours before your originally scheduled departure to about 23 hours after. You can also same day standby to any flight that has the same routing within that time frame. Free same day changes for gold+ is what I consider the best benefit of the United frequent flyer program and is pretty much THE reason I stick with United.
If you simply fail to show up for your flight, it will automatically cancel, but the few times I've accidentally done that, and I got in touch with United just afterwards (usually sometime between just after the check-in deadline to less than an hour after the flight), they've just put me standby on the next flight. YMMV. I certainly wouldn't just ignore the flight and attempt to get another flight hours later.
Short version, while the app and kiosk will lock you out of SDC after the check-in deadline, an agent will probably still do it for you for some short time period after departure.
Jan 26, 2018, 8:53 pm
#3209
FlyerTalk Evangelist
Join Date: Oct 2006
Location: SFO/SJC
Programs: UA Silver, Marriott Gold, Hilton Gold
Posts: 14,880
I did not read all your posts, but how practically to standby a later flight without showing up at the airport for the original flight? Can you just call from anywhere? The only thing for sure is that no matter what you do, you do it before the original flight departs (or 30 minutes before that). Will then the app show the new (standby'd) flight?
Jan 26, 2018, 10:23 pm
#3210
Moderator: Budget Travel forum & Credit Card Programs, FlyerTalk Evangelist
Join Date: Aug 2002
Location: YYJ/YVR and back on Van Isle ....... for now
Programs: UA lifetime MM / *A Gold
Posts: 14,426
IIRC, and I have not done this in a couple of years, you can ONLY standby IF there are no seats available on the flight, i.e. IF you CANNOT do SDC to that flight, but you can standby for it.
Real life example:
I was booked on last flight of the day and wanted to fly on second to last flight, but only FC was available, so I could NOT do SDC as my original coach fare was NOT available with coach booked full.
GA was not happy, but at my insistence, he did put my on standby list, and low and behold, as 1K I was #1 on standby list, though coach was still full.
A couple of misconnects by late pax in coach, and I went from #1 on standby list to a seat in FC thanks to seamless clearing into my original booking class and FC having two seats empty.
Granted, I've sat in coach way too many times, but it was amazing to watch this unfold as I got home a couple of hours earlier, in FC no less, even if it was an hour puddlejumper.