This is causing me a small amount of hassle with domestic bookings that our corporate TA makes, but doesn't pass the passport number across on. It seems that the API part of MMB is not offered for domestics, so I can't add it there either. If a POUG is then offered it seems because of the TA origin there is a to need a call to BA, but they can't then get me past security checks.

I haven't worked out yet whether the passport number not being sent is a policy on domestic bookings, or whether some of the data they are holding is incomplete.