Hi. Slightly convoluted one here:
a friend of mine wants to join the front end of a business trip to Tokyo on the same flights. I'm flying LHR-HEL-NRT on a BA code (BA then AY metal) in J but he can't stump that at the price today.

He is looking at booking the same flight via BA but I've read about the AY bid for J seats 7 days pre flight. But I ant find out how to do them. Can I do this on BA code or is this just AY coded flights? And how do I get the right Y ticket?

Any help gratefully received. TJH