AA says you canot use British Airways between the US and the UK using their awards. So I have a question- lets say I want to go to Berlin from the US using their AA award for 40,000 miles. Would I be able to book Houston to London (on American) then connect on to Berlin using Brisitsh Airways?

Yes. And you'll have to call AA to book it, as you cannot book award tickets on partner airlines online.

You may not fly BA using AA frequent flyer miles from the U.S.; but you can use BA frequent flyer miles from Canada to Europe.

This is something I did two years ago, thanks to the kind folks @ AA reservations.

My flight was Toronto to LHR.

Hi Bill, I've taken similar trips many times where I flew AA to London then BA to some other part of Europe. As yk said you will have to call AA and they will charge the booking fee for booking via phone. I think it's strange they charge that fee since you have no option to book on line but that's the way it's done.

You don't say when you plan to fly, but 40K is AA's off-peak (Oct. 15-May 15) redemption rate to Europe. The rest of the year, you'd need 60K. Even then, 60K doesn't give you the choice of every single date. Flexibility is the key to finding something here.

I would book my flights when the 40k award is available - we are flexible in that regard.