Okay, here's how it works. You receive a letter from the ABS which has a unique code to enable you to log on. The code is tied to either your address (I think this is the case) or your name. Probably not number two. If there is no logon from the code you have, you haven't completed the census, and someone will come knocking on your door, I guess. Begs the question of how can they know your letter wasn't stolen from your mailbox, or lost, or eaten by your dog, but this *is* the government, so it's not surprising.