Recently given United nice cancelation policy I started using Future Flight Credits quite a bit.
Goodthing is that you can use multiple FFC on a single booking as it's rare to have new booking price match the original one exactly.
The problem I see (mulitple time already) is that any leftover have "Travel By" date set to the earlier of certificates.

E.g. let's say I had

• FFC for $12.35 on booking ABCDEF expires 1/15/2024
• FFC for $1000.00 on booking GHIJKL expires 10/1/2024

Now I book a new flight for $112.35 using this two certificate. In results I see:

• FFC for $900.00 on booking GHIJKL expires 1/15/2024.

In other words an "travel by" date is reset to an earlier (fully used) certificate, even though certificate is still accounted under the later booking. E.g. now for my family 3 people on same canceled booking have certificates expiring in the second half of the year and 1 person expiring in Q2. It looks like a glitch for me, yet I saw this at least twice. Should I contact United to correct the date or are there any other information / suggestions?

See this thread for instructions on how to extend the expiration date: Understanding/Using UA Electronic Travel Certificate(ETC) & Future Flight Credit(FFC)

Well, I briefly looked into it (it's 70 pages) and yes, I can probably extend it by booking / cancelling trick. But my question is more if the thing that happended is a glitch / bug and I should contact United to reinstate the original expiration date. I would better do this as (a) this would probably prompt United to fix the bug (b) I prefer not to use loopholes unless really required.

I've noticed the same thing you described happen for my FFC also. However, they were still far enough in the future for me that I didn't feel motivated to pursue extending ever, since I could still use the I-also-think incorrectly-shortened FFC easily.

Let us know what they say if you contact, please.

My case is very weird. The original one's expiration date is Sept, 2024. After I used it for a ticket, just noticed that the residual credit's expiration date is end of this year. 12/31/2023 Why? How to deal with this.

is it possible to call united to solve this？

Might be. Please post in that thread if you attempt to do so.

probably just easier to book a new flight where departure is prior to the expiry date, using the FFC as a form of payment, then canceling >24 hours and getting a new FFC, where the expiry date will now be 1 year from the new PNRs date of issue, which will be Dec. 2024.

I called 1K last night about this issue, was asked to wait for the customer service to contact me. ...

Just got the reply from United...... so strange
Thank you for contacting United Customer Care.
Since your credit was partially redeemed, we are unable to comply with your request
As the original recipient of the certificate, you can arrange travel for another person as long as you don't sell it or make a barter arrangement in exchange. Please visit united.com or call 1-800-UNITED1 for booking information. You can also stop by one of our worldwide offices listed here: https://www.united.com/web/en-US/con...s/default.aspx.
We appreciate your business and look forward to welcoming you on board in the future.
We thank you for your continued loyalty, as a valued Premier 1K customer.
Regards,
Sesem
Customer Care

I feel like they don't understand the issue. 😕

I then need to book a new ticket then cancel to see if it works for me to get a new future credit

I've noticed the same thing.

IIRC, if using your example, when selecting GHIJKL on the payment page, there would be some verbiage that comes up that says that there will be $900 expiring 10/1/2024, but also that any residual credit will take the earliest expiration date of any combined credits.

Would be good for UA to fix that message, since these seem to be conflicting statements.

Yes, this is exactly what happens.

With credit ABCDEF for $10 expiring 2024/01/10 and credit GHIJKL for $900 expiring 2024/10/01 applied to a $600 ticket purchase, the payment page will say new credit of $310 expires October 1, 2024 (which is appropriate), but then the actual credit will be coded GHIJKL and will expire January 10, 2024.

I know they read these forums, and I'm sure that (plus OP) is a clear enough description that they can find the problem and fix it, but let's see if they do it. 🙄

I just purchased a ticket traveling in Jan.2024. Interesting, I succeeded in applying the credit (reseted to earlier travel date end of this year). It seems United Airline system still recognizes the previous expire date.