Are you sure? From the fare rules at ba.com:

BRITISH AIRWAYS SALE FARES FROM THE UNITED STATES TO UK AND AREA 2/3 APPLICATION AREA THESE FARES APPLY FROM THE UNITED STATES TO UNITED KINGDOM/AREA 2/AREA 3. CLASS OF SERVICE THESE FARES APPLY FOR ECONOMY CLASS SERVICE. TYPES OF TRANSPORTATION FARES GOVERNED BY THIS RULE CAN BE USED TO CREATE ROUND-TRIP/SINGLE OPEN-JAW JOURNEYS. CAPACITY LIMITATIONS THE CARRIER SHALL LIMIT THE NUMBER OF PASSENGERS CARRIED ON ANY ONE FLIGHT AT FARES GOVERNED BY THIS RULE AND SUCH FARES WILL NOT NECESSARILY BE AVAILABLE ON ALL FLIGHTS. THE NUMBER OF SEATS WHICH THE CARRIER SHALL MAKE AVAILABLE ON A GIVEN FLIGHT WILL BE DETERMINED BY THE CARRIERS BEST JUDGMENT RULES NOT APPLICABLE RULE 35 PASSENGER EXPENSES ENROUTE RULE 1018 SENIOR DISCOUNT OTHER CONDITIONS THESE FARES MAY BE COMBINED WITH CREATE YOUR OWN VACATION BRITAIN AND EUROPE AND/OR LONDON PLUS PROGRAM. FREQUENT FLYER MILEAGE MAY BE EARNED BUT NOT REDEEMED.