I've got an upcoming ticket with 3 legs, the first of which is operated by AA. The other two legs, one of which is longhaul, are operated by BA and the ticket is bought through BA.com. Is it possible to check-in online on BA.com for this trip? If it is, can it usually be done without hiccups? I'll be looking to select seats at check-in and if there's a risk I'll be asked to do airport check-in I'd probably pay to pre-select seats on the longhaul leg. I've had trouble with online check-in on other airlines where codeshares are involved, that's why I'm asking. I've got no status so I'll have to pay for seats or wait to check-in opens.