Originally Posted by
Upupintheair
Would be convenient if BA would allow to enter 2 or more passport details and that you can then select the one you wish to have connected to the specific trip.
Yes, and it shouldn't be beyond the realms of IT specialists.
I have full UK and Swiss passports (and a Swiss ID card which is very practical in most of Europe). The Swiss PP/ID is marginally more useful - no Turkish visa and in theory at least lower Chinese visa costs.
If the dinosaurs have their way in 2019 and travel to EU countries changes, I can see my UK passport becoming redundant except for the US. That would be a sad day. I'd like the option of using either or both for API.