Originally Posted by ConradMZ

I met this problem, too, connecting in LHR from ORD to FRA with an overnight in London (the daytime AA flight from ORD to LHR is one of the few connections to FRA not requiring sleeping (or staying awake) on the plane overnight). No one at ORD could give me much of an explanation, and no one could tell me for sure what would happen in LHR--would I be able to immediately re-check the bags with BA before leaving the airport, rather than lugging them into the city and back? Turned out that at LHR I spoke to a baggage attendant and she agreed to watch out for the bags and re-tag them to FRA for the following afternoon's flight--didn't even have to wait for them to come out on the belt! So maybe, if the baggage claim personnel at MIA are as accomodating, you will get the next best thing to having bags checked through.