Originally Posted by
Foltan
Assuming you haven't accidentally chosen an Iberia service, I would guess that it's because of the mixed-class itinerary.
You're given different Avios > Cash ratios and quantities for Business vs Economy, so when it's a combined itinerary, it probably isn't capable of working out a 'rate' for you.
See this link for the usual payments amounts for the two different classes:
https://www.britishairways.com/en-gb...s/part-payment
Thanks for your reply. I've just called BA and they couldn't do it over the phone either. The lady I spoke to says she couldn't figure out why and was adamant that the mixed class wasn't an issue as she'd done that before. I'm not sure whether she's right though. I wonder if the LGW/LHR aspect is also an issue.