Originally Posted by
LondonAussie
Cathay P class also credits normally to other OneWorld airlines programs - AA, AS, AY, IB, JL, MH, QF, QR.
BA is the exception and the outlier here.
As for changing your FF program between flights, this should be possible by loading your booking into the Finnair or RJ sites and first removing your BA EC number and then adding your other program number.
No IB does not allow earning in P class fares either. Hardly surprising siven BA and IB programmes are cut from the same cloth.
QR would be of interest to me given they also operate in Avios currency and Avios can therefore be transferred between programmes into BA. But I guess everyone is going to be different here and others may have other priorities. Tier/Status points in any case won't be transferrable and with remain with the programme where points ate earned.