You won't be able to change your basic economy ticket once you've bought it. However, if you cancel your reservation within 24 hours after making it, you'll get a refund.
For non-refundable tickets, travellers will be charged an American Airlines cancellation fee of $200 for domestic flights and $750 for foreign flights. However, you won't be assessed a cancellation fee if you cancel your reservation within 24 hours of making it.
On a non-refundable ticket, a full refund is not possible. The cancellation fee will be deducted from the total cost, and the balance will be given to you as a credit against a future trip.
Refundable tickets are easy and affordable to cancel, and whether the ticket is cancelled or not, there is no cancellation fee.
