Originally Posted by
EvilDoctorK
This sounds absolutely fine ( I would have expected 10% of the base adult fare too ) .. I'd just love to pay it in advance rather than have to mess around at checkin , especially in MIA on a relatively short layover
You could try to have AA at LHR do the lap-child ticketing for MIA-CUN-MIA well in advance of your trip to the US. Not sure how convenient that is for you, but that is what I would do if in such circumstances.
When it comes to even Canada-US lap-child tickets, I'd be looking for a ticket number for the lap-child well before the day of travel.