SF, you can apply online for baby bonus and ftb up to 3 months before EDD. claim will be assessed and processed "pending proof of birth" - when you deliver your twins, you fill in the paperwork that is given to you at the hospital (which does seem to double up some of the information, but it has to be done!), and submit that. will take about 3 weeks to process your claim from that time. you can send in the reply paid envelope, and when FAO finish with the forms, they will forward to medicare to add twins to card. IF there is a chance you will need to see a pead or anything before you get that registration info back, you can submit form at medicare, and they can add babies while you wait, giving you a temporary "receipt" which is the same as your card. i had to do this when DD was born as she had to see the pead a couple of days after discharge from hospital and we weren't in a place to pay out a couple of hundred dollars and wait weeks for medicare refund