On a round Europe trip I booked a flight from AMS to LHR through the BA web site. I booked the lowest cost flight. Higher cost options included increased baggage allowance. I assumed that as an AA EP/Emerald I'd be entitled to a free checked bag. When I did my on-line check-in, I was prompted to pay for bags. I called the EP desk to make sure my status was correctly set, which it was, and they connected me to the BA "crossover" desk to confirm my entitlement to free checked bags as an emerald flyer (which they did). They were unable to change my check-in to include a free checked bag (I think emeralds get 2, but I only needed 1), but assured me they would fix it at AMS when I checked in. At AMS, I was informed by the BA agent that I'd purchased a "handbag only" ticket and was not able to check a free bag. I pointed out my status, and that their web site indicated emeralds were entitled to additional free checked bags (so ticket gets you "0", I should be entitled to 1 as an emerald). They refused and after some discussion, I paid a €75 fee for my bag. At online checkin that would have been €50. Just wanted to post as a warning, particularly since my qualification for a free bag had been confirmed by BA on the phone. If your ticket is "handbag only" (and I have no recollection of seeing this, only that I didn't want to pay the up charge to check a bag when I booked the flight) Emerald baggage privileges don't apply.