Question: how much is it to extend a flight on american airlines?
Answer: American Airlines — Has a $200 (£160) change fee on paid fares (other than full-fare refundable tickets) for domestic flights, and up to $750 (£600) for international flights. Same-day changes are $75-$150 (£60 – £120) in economy and free for business and first-class passengers on paid fares.