Originally Posted by GUWonder

I’ve gotten a countless number of lap child tickets issued at airports across here in Europe. Sometimes the airport is the best or even only place to get it done properly after hitting dead ends over the phone for already ticketed adult itineraries or when the airline already messed up the booking of the lap child.

US domestic itineraries don’t require lap child ticketing, as lap children are free on domestic US flights and can be added easily over the phone by operating carriers even for already issued award tickets

No more than one lap child is allowed per ticketed adult. But two adults can have a lap child each.