Since Wednesday, July 22 American Airlines has been able to apply up to 8 credits from cancelled ticket to a single new ticket purchase.
When you cancel a trip, any residual value is stored alongside your ticket number. The ticket number is what’s used to apply a credit to a new reservation. American’s AACoRN system now lets an agent enter multiple ticket numbers – up to 8 – that have credits attached to them, and apply them all to a booking.