I've been following this thread for months, but even after going back and re-reading the past dozen pages, I'm still hopelessly confused. (Apologies in advance if the answer is there, happy to contribute to building the wiki once the answers are clearer.)

I have 2 trip credits: one for $1,200 (expires May 15, 2024) and one for $3,000 (expires July 15, 2024).

I just booked a $300 flight for April 2024 using the smaller of the credits. Within 5 minutes, I received a trip credit back for the difference of $900 with the original May 2024 expiration date. No surprises there: as expected there was no extension on the remaining balance. (If this had been a FLIGHT credit, the expiration date for the $900 would have been one year from today.)

I am thinking ahead on how to extend these credits if necessary, because even if I take a few small trips, I don't know that I'll have $3,900 worth of personal travel until later this year.

If I make a speculative booking for October 2024 using both of these credits, and end up having to cancel, will I get back one new trip credit with a May 2024 expiration date? What happens if I cancel after May... or for that matter what if I cancel in August? Do I lose the whole value of the credit?

Depending on the answer, I might need to take a very different approach on using these credits (such as taking a trip just to avoid losing the credit, booking flights for family members, etc).

UPDATE from 2/27/24: I ended up having to cancel the $300 flight, and actually received a trip credit for $300 valid for one year from today! I'll want to see more data points that this happens consistently, but this is good news.

Note: I'm using round numbers in this thread for math simplicity. Actual credits/flights are obviously not such round numbers.