Originally Posted by
MSPeconomist
OP says it's UA.
I've never been asked by DL during OLCI whether I have a lap kid.
On Delta, you can actually add your own lap child online by going under "special services." I really like that a lot as it saves a phone call, but sometimes it can be a pain- you can only sit in certain seats on certain planes with a lap child, and if you're in one of the "illegal" seats it just rejects the lap child without telling you which seat is an issue.
I would call United or search their website for information on adding the lap child. Generally doing it ahead of time is the way to go, although that doesn't mean that you won't have to repeat the info three times anyway. AA & DL will still let you OLCI with a lap child; I am not sure about UA.