As some above are looking at including CX in a TP run: please make sure you do not book into the 'P' fare - otherwise you will earn exactly 0 TP.
I don't know why it doesn't earn any TP, since the cheaper 'I' fare earns full TP. Seems like an oversight from BAEC.
Just book the lowest PE bucket and get the same TP's as business.
Looks like BA's Tier Point calculator is in some kind of meltdown. I got just over 7,000 avios for this sector in 'I' class as opposed to the 20,241 shown here.