DON'T BOOK BUSINESS CLASS ON BRITISH AIRWAYS! Choose any other airline if possible. Walk if you have to.
I experienced the same problem with BA as Jeanne F., who posted on April 1st. I booked business class flights for my wife and myself through American Airlines, flying round-trip Denver to Dublin. American Airlines shows that they partner with British Airways for the outbound flight. When it came time to make BUSINESS CLASS seat reservations, it was no problem on the AA leg of the flight. British Airways charged me $352 to make my seat reservation. I am livid. I
complained to BA, AA and the US DOT. AA and BA told me tough luck. No response yet from the DOT.
DOT regulations require airlines to post additional fees, including seat and luggage on their home page. I booked, and PAID AA for this flight and they DO NOT HAVE anything posted about their "partner" airline, BA charging additional for seats.
I'll walk before I fly BA or AA in the future. From this point on, United Airlines and UA partners will have my business.