Originally Posted by
djp98374
As above poster said…
since you have miles posted it was a good flight number to earn on ( some flight number groups you don’t earn on) and then it’s based on class of service in the ticket and then see the AA/BA chart based on who you booked thru for the reward percentage formulae
It isn't who you booked through, it is the carrier on the flight number. As mentioned earlier, AA will sell me a BA codeshare on a flight operated by AY - Finnair. So, I pay AA for the flight. The flight has a BA flight number but AY flies me from point A to point B.
I earn according to the BA charts (all BA codeshares operated by AY are in range). That is favourable since AY J only earns a 25% COS for I & R fares. With an AA flight number, it earns a 50% COS bonus and COS is both EQM & RDM, while with a BA flight number it earns not only the 50% COS bonus but also earns an additional 100% RDM bonus. A 5000 mile J (R, I) flight with a BA flight number would earn 7500 EQM & 12,500 RDM (250%) before any Elite bonus; who sold you the ticket and who operated the flight is irrelevant.
You can have an itinerary that has multiple carrier flight numbers so you need to refernce the appropriate chart for each segment.
James