Originally Posted by
nicolettecoe
To book, search for a qualifying flight and enter your unique Code into the “Promotion Code” field on the Price Quote page of the ba.com booking form (Not the e-voucher field). The Code is not available through other channels or at the airport.
OK, so forgive the perhaps obvious question, but what happened when you tried to use this field during the booking process? And did you see precisely this screen? This can be a dummy booking for example.