I suppose it is time for you to learn what people mean when they talk of BIS miles. With apologies, but it stands for "Butt In Seat". That is who gets the miles - the person flying.

I'd guess your infant will travel in somebody's arms for a while so won't actually be a ticket holder, but do be sure to get him/her signed up before the first real paid-ticket actual-seat flight.

Lots of us wish there was a family or group number under which miles could accumulate, but so far the airlines haven't seen it that way. No "baskets".

One person - one account - one batch of miles. On the other hand, you can use your batch of miles to buy a ticket for anybody else.

When you buy three tickets, there are three separate places to enter the frequent flyer numbers. One for each person.

After you think you know which program or programs you want to sign up for, you might go into those individual airline areas here and test your assumptions and understandings. "Airline Programs". People in the United area really understand United rules, ... etc.

Because my area is so dominated by Delta, I'm really only reasonably well versed in Delta rules. For the record, I learned the hard way about the fact that I only got 50% miles for my Delta account from a Continental flight. A flight from MSP to Dublin. Missed lots of miles. I argued/whined a while, but it really was so stated on the itty-bitty print deep on Delta's web site.

Romelle