Originally Posted by
guv1976
I know that AA does not charge for lap infants on domestic travel; not sure about U.S.-Mexico flights. Unless you want a separate seat for the infant, I would call AA and ask if there is any charge for lap infants on the JFK-CUN route. If there is no charge, just book for two adults and one child on ba.com.
AA charges 10% for lap infants on all international flights.
OP for BA to get award availability, there needs to be AA Saver availability. Looking at for JFK-CUN May 8th, the only AA non-stop shows availability but it looks like it's an AA web special award, which is different than a Saver award level. There might be availability on a one stop flight, but I think that brings up search issues with BA.com. Also, note that AA.com will also show JetBlue flights which may not be available to you using Avios.