Originally Posted by
DownUnderFlyer
Sorry, I didn't understand you correctly. Yes you can use BA miles to upgrade flights on BA.
But only if the ticket has been purchased from BA.
From the BA board ultimate guide:
Another extremely important caveat is that you can only upgrade a ticket that has been purchased directly from BA. This applies to ba.com or over the ‘phone. If you are in North America, you can upgrade a ticket, but it must have been purchased from a “BA Preferred Travel Agent”.