Thank you Savage25 for your reply. Since we did not book online via Singapore website we could not retrieve the booking. And, I know that if we did that then we could retrieve the booking by logging into as a KrisFlyer member (and I am) - but only for my booking and no one else. Your saying that SQ may use a proprietary system probably explained why we could not retrieve the booking through one of the online reservation services. And, you are right about retrieving SQ flight booking through a travel agent. Last year, I booked some SQ flights through a TA and I noticed there were 2 reference numbers - using the TA's reference number I was able to retrieve the booking (and it also showed a different reference SQ number).