Certainly we found that we couldnt check in online with Cathay Pacific in June this year with Daisy's passport expiring at the end of August. They were looking for 6 months passport validity.
Fortunately we did this 48 hours before the flight and living in London were able to make 2 trips to the Philippines embassy to obtain an emergency passport extension before we travelled.
We then managed to travel and the only time the extension was commented on was leaving the Philippines.
I assume that had we turned up at LHR with the original passport we would have been refused travel
