So if I have a cancelled ticket that was originally issued on July 16th, 2018, and I today use that credit, pay the change fee and book a new ticket, does:
1. travel need to occur before July 16th, 2019?
2. If I cancel this new ticket again, would it be valid one year from today, or would it expire in July since that will be one year from original issue date?
Once reticketed, the 1-year clock starts again based on the new re-ticketing date.
So yes you can extend this multiple times but you will have to pay a change fee each time.
This approach is limited to the original ticketed passenger. is limited to
An alternative solution is to change to
an ultra-inexpensive flight and get an ETC which can be used by others.